Can Sex Change Your Period?


Can sex alter your monthly period? The short answer is no, not really. According to Planned Parenthood, the only circumstance when sex can ‘change’ your period is if you get pregnant, in which case your period stops completely. 

Having said that, there are several factors that can impact your ability to have a period, some natural and some not. So let’s dive right in.

How Pregnancy Affects Your Period

During your reproductive years, if you have unprotected sex near or during ovulation there’s a solid likelihood of getting pregnant. Your ovary releases a follicle (oocyte) each month, around day 14 to 16 of your menstrual cycle. After the oocyte is released from the ovary, it moves into the fallopian tube and matures into an ovum (aka egg). 

The egg stays in the fallopian tube for 12-24 hours, waiting to be fertilized. Your sex drive may increase at this time. It’s worth noting that sperm can live inside a female body for up to 5 days so the window for getting pregnant is actually longer than just a couple of days. 

If an egg is fertilized and implants in the uterine lining, a couple of key hormonal changes happen to support the pregnancy. Levels of progesterone and human chorionic gonadotropin (HCG) spike which prevent the breakdown and shedding of the uterine lining and cause periods to stop. 

It is completely normal and expected for your period to stop during the entirety of your pregnancy. Pregnancy can be confirmed with a pregnancy test. Breastfeeding can also delay the return of your period. 

Why Do I Sometimes Bleed After Sex?

Aside from pregnancy, there really isn’t a way sex can dramatically change or affect your period or menstrual cycle. The reason why this misconception exists is that many women experience spotting or bleeding after sex. 

It’s important to keep in mind that not all vaginal bleeding is menstrual bleeding. Non period bleeding after sex can happen for a variety of reasons, including vaginal tears caused by dryness, infection, or in some cases, certain types of cancers.

Vaginal Tears 

Sometimes you can endure minor vaginal tearing during sex. This can lead to some light spotting or bleeding afterward. Typically, your vaginal walls are covered by a layer of mucus that keeps things lubricated. A lack of mucus leads to dryness.

If you have sex while experiencing vaginal dryness, there is a higher risk of tearing and bleeding. According to The Cleveland Clinic, vaginal dryness can be a side effect of the following: 

  • A drop in estrogen levels (commonly occurs close to menopause or while breastfeeding)
  • Certain medications like antihistamines 
  • Lack of foreplay before sex

Minor tears are normal and not uncommon; however, if you notice excessive bleeding right after sex it could be an indication of more damaging tears. If you experience heavy bleeding after sex, you should visit your doctor. 

To help relieve uncomfortable sex or spotting due to vaginal dryness you can try regular drug store lubricant before and during sex. You can also visit your doctor and discuss the option of prescription medication for hormone replacement therapy to replenish the mucus lining of the vagina. 


If you experience pain or a lot of bleeding after sex it could also be a sign of infection. When there is an infection of one of the reproductive tract organs it’s referred to as Pelvic inflammatory disease (PID). PID can lead to pain and/or bleeding during and after sex. 

There are many risk factors that can lead to vaginal and reproductive tract infections. 

  • Sexually transmitted infections (STI), like chlamydia and trichomoniasis, produce bacteria that can sometimes travel from the vagina to one of the organs of the reproductive tract including the cervix, uterus, fallopian tubes, and ovaries.
  • Unprotected sex with multiple partners is a big one, so it’s always recommended to use a contraceptive, like a condom, when having sex with someone whose sexual history you don’t know very well.
  • Douches are another common (but lesser-known) cause of infection. Women typically use douches because it helps them ‘feel clean’ but they actually are responsible for killing a lot of the ‘good’ and ‘healthy’ bacteria in your vagina. Douches offset the balance of harmful and good bacteria and can quickly lead to a PID.

PIDs often cause lower abdominal pain, smelly discharge, and irregular vaginal bleeding. If you suspect you’re suffering from a PID you can visit your doctor who will prescribe you antibiotics or other medication to help. These infections will rarely-if ever-go away on their own.

Gynaecological Cancers

Gynaecological cancers include things like cervical cancer, uterine cancer, and vaginal cancer. Post-sex bleeding is often an early sign of these cancers. Other symptoms that usually accompany gynaecological cancer include abnormal vaginal discharge and pelvic pain or pressure. If you notice these symptoms, you should visit your doctor to rule out the possibility of cancer.

The American Cancer Society estimates that 113,520 women in the United States will be diagnosed with cancers of the reproductive organs in 2020. Developing cancer of any kind is very serious. So, it’s extremely important to take preventative measures for early detection and treatment. 

The best way to prevent cervical cancer is to have regular screenings and never miss a Pap test. A Pap test (sometimes referred to as a smear test) can detect any irregular cervical cells caused by the human papillomavirus (HPV). HPV is a precursor to cervical cancer so detection and treatment of HPV ASAP is a very effective preventative measure for cancer.

HPV can be prevented by either getting the vaccine (though, it’s not recommended if you’re over the age of 26) and using protection, like a condom, during sex.

Factors That CAN Change Your Period

The menstrual cycle is a delicate process and rarely runs like clockwork. It’s totally normal to experience changes in your menstrual cycle and period month to month. While sex doesn’t affect or change your period, there are a number of lifestyle, emotional, medical, and physical factors that can cause changes to your period.

Missing One or More Periods Is Called Amenorrhea

When a woman misses one period or more, it’s referred to as amenorrhea, as explained by The Mayo Clinic. Some of the things that delay or stop your period can be cause for medical concern but some are natural as well. So, if you notice anything unusual try to avoid going into panic mode! 

Natural Causes of Amenorrhea

    • Pregnancy (as mentioned above)
    • Breastfeeding: Breastfeeding can delay the return of your period for up to 6 months. and is referred to as lactational amenorrhea.
    • Perimenopause: Perimenopause means “around menopause”. Hormonal changes and estrogen irregularities during this time cause periods to become more infrequent.
    • Menopause: Menopause happens when your menstrual cycle comes to a complete end and is medically defined as having gone 12+ months without a period, 

Emotional & Lifestyle Factors That Cause Amenorrhea

    • Extreme stress: Extreme stress can affect the functioning of the hypothalamus which is a part of your brain responsible for hormone regulation. Once your level of stress decreases, periods should return to normal. 
    • Extreme exercise: Female Professional athletes often experience interrupted menstrual cycles. The effects of extreme exercise often lead to a very low percentage of body fat which causes hormone imbalance and can lead to temporary period loss. 
    • Extreme weight loss: Women who are 10% or more below normal weight may experience hormonal changes that interrupt or halt ovulation and menstrual blood flow. 

Physical & Medical Factors That Cause Amenorrhea

    • Polycystic ovary syndrome (PCOS): PCOS is characterized by higher, sustained levels of hormones than normal.
    • Uterine fibroids or polyps: Growths on the inner lining of the uterus can cause irregular menstruation and amenorrhea.
    • Uterine scarring: A build-up of scar tissue on the uterine lining can interfere with the normal shedding of the endometrium. Scarring can be caused by procedures like cesarian section, polyp removal, or dilation and curettage (D&C) surgery after a miscarriage. 
    • Birth control: Birth control pills are meant to regulate hormones so they naturally will disrupt your normal rise and fall of hormones.
    • Other medications: Some medications like chemotherapy treatments, antidepressants, and blood pressure drugs can cause periods to stop.
    • Hormone production disruption: Any other condition that can cause a hormone imbalance like an under or overactive thyroid gland or a tumor on the pituitary gland can lead to amenorrhea.

When to See a Doctor

Your period can change each month and as you get older. Many of these changes are totally normal and nothing to worry about. Having said that, there are times when these changes are cause for concern. As a general rule of thumb, you should always visit your health care provider if you:

  • Experience abnormally heavy or very irregular periods
  • Feel unusual pelvic pain
  • Miss one or more periods
  • Notice unusual and smelly vaginal discharge