Can I get pregnant on my menstrual cycle?

If you've only had intercourse while menstruating, you might think that there's no way pregnancy could result. It is important to know, however, that some women can get pregnant while menstruating. Whether you are one of those women depends on how your unique menstrual cycle works.
The average woman has a 28-day menstrual cycle and ovulates 14 days after she ends her period. Because sperm can live for up to five days and eggs remain viable for about two days, the average woman can usually get pregnant if she has intercourse sometime between day 10 and day 17 of her cycle. This is because she is fertile for a few days mid-cycle, but is not fertile for the rest of her cycle.
The important phrase, however, is "average woman." You may have an irregular menstruation cycle. You may not ovulate on day 14 but instead on day 10 or day 20. You also may release an egg from one ovary on day 14, but may also release an egg from the other ovary on day 24, making it possible for you to conceive while you are menstruating. The fact that your uterus is shedding the lining may make it more difficult for the fertilized egg to implant, but it is not impossible for the implanting to happen. It’s just less likely.

How can you tell if you have an irregular menstrual cycle or ovulation cycle? You probably will never know unless you either get pregnant, realizing that the only time you had intercourse that month was during your period, or if you have fertility issues and go to a doctor, who will perform tests to determine when you ovulate. If you have very short cycles, you are more likely to be able to conceive while you have your period.