Can having sex affect ovulation or menses? I had quite regular periods before I started having sex at age 17. Then my periods starting coming late -- by seven to 10 days. I was using condoms at the time, but because of the stress this caused, I started taking birth control pills (condoms just didn't seem trustworthy enough). The pills keep my periods regular now, and I can't tell if having sex affects them.

Erin

In rabbits, the answer would be yes. We know that rabbits ovulate after having sex. But in humans, we do not believe that having sex affects the duration of your menstrual cycle or whether you ovulate.

Many factors can cause irregular periods, including stress, weight gain, diabetes, or thyroid or pituitary gland problems, for example. For women with irregular cycles and no other symptoms, most physicians begin by prescribing birth control pills to regulate the cycles. If you have other medical complaints or do not respond to birth control pills, further evaluation is advisable.

Even though the birth control pills are successful at restoring a normal monthly menstrual cycle after two to three months for most women, they do not cure any underlying problem. For most women taking birth control pills for cycle regulation, once they stop taking the pill, the menstrual irregularity will likely return. So, although your cycles may be regular while you are on the pill, you may want to consider other factors that may have been contributing to your irregular menses.