Many women rely on the days of the calendar instead of more tried-and-true methods of birth control, such as condoms and oral contraceptives. Some of those that are considered "safe" may be the days when a woman is on her period. But can a woman get pregnant on her period? The answer is a resounding "yes." A woman can get pregnant any time during the month, but she is particularly vulnerable during ovulation. Because sperm can survive for up to five days, ovulation may occur during that time. Most women do ovulate 10 or more days after their periods, but for women who have very short cycles, that period of time also is shorter. This may allow for sperm to survive long enough for an egg to be released during ovulation and fertilized. Another plausible scenario is that an egg may be released during ovulation and not fertilized until the menstrual cycle starts. If the egg isn't shed and is fertilized, a pregnancy can result. One other scenario might be the appearance of breakthrough bleeding around the time of ovulation. It is possible to spot around the time of ovulation, when the egg is released. It isn't a period, and it is very possible for a pregnancy to occur, regardless. There are some hallmarks of pregnancy that could mimic a period as well. Women who bleed or spot during the period when their periods normally occur actually can be pregnant. When the fertilized egg attaches to the uterine wall, then the process may cause bleeding and cramping; in other words, symptoms of a period. Many women mistake implantation for the onset of the menstrual cycle or even an early miscarriage. This bleeding is different in that it may just last a day or two. The best way to know if you are pregnant is to visit your OBGYN, and the same goes for any atypical or heavy bleeding that concerns you.