Can You Get Pregnant Without Having a Period?

Your menstrual cycle can be misleading. Some women have regular periods without the ability to become pregnant, called an anovulatory cycle. Other women who experience irregular cycles or the absence of a period can still become pregnant. Fertility has less to do with menstruation and more to do with healthy ovulation.

Ovulation not Menstruation

Ovulation is when you body releases an egg from your ovaries through your fallopian tubes and into your uterus. Once the egg passes into the uterus, you are fertile for 12 to 24 hours before the egg breaks apart. If sperm penetrates the egg before it breaks apart, the egg embeds itself into the lining of your uterus where it can grow into a baby. Ovulation typically occurs approximately two weeks before you have your period, your body's way of disposing of the unfertilized egg and unused lining.

If you are not having a period or you are having an irregular cycle, you can still get pregnant because ovulation occurs before your period, and ovulation can restart at any time 1. Young women can even become pregnant before their first period. There are no concrete physical signs of ovulation, so you could be ovulating and not know it.

Irregular cycles generally make it difficult to conceive, but that shouldn't stop you from using protection or birth control if you want to avoid conception. If pregnancy is your goal, there are ways to stimulate a regular cycle to increase your chances.

Difficulty with Conception

A regular cycle makes it much easier to conceive. The American Pregnancy Association estimates that ovulation begins 11 to 21 days after the start of your last period, and 12 to 16 days before the beginning of your next period 2. And there are a variety of methods to predict peak fertility during a regular cycle, including the calendar method, basal temperature method and the cervical mucous method. There are also kits you can purchase that predict ovulation by detecting luteinizing hormone, a precursor to ovulation.

It is impossible to predict the window of fertility if you are not having a period or are irregular. You need to know the dates that your periods take place in order to estimate ovulation, and none of the prediction methods will work consistently without tracking a regular cycle.

Jump-Starting Your Cycle

Up to 40 percent of cases of infertility in women are caused by an irregular cycle. Your doctor will test you for other medical conditions that may cause infertility before treating you for an irregular cycle. If those are ruled out, your period will likely be induced with the hormone, progesterone.

Encouraging a Healthy Egg

After jump-starting your cycle, your doctor will probably prescribe chlomiphene citrate, also called chlomid. Chlomiphene changes the balance of hormones in your body to stimulate the release of a healthy egg. You'll start with a low dose of the drug, likely 50 milligrams in pill form, and take it daily for five days starting on the third, fourth or fifth day of your period. Ovulation will occur seven days after you've taken the last dose. Because sperm can live in your body for up to five days, engage in intercourse for five days leading up to ovulation.

Chlomiphene's efficacy is well documented in the journal,Reproduction. The drug stimulates ovulation in 70 percent of patients, and 40 percent of those successful patients will conceive, according to this peer reviewed journal. The drug is so effective that the chance of a multiple pregnancy jumps from the average of 1 percent to 10 percent. But if the treatment is unsuccessful after six months, you'll likely be referred to a specialist for a consultation on alternative treatment.