Can you have sex if you are pregnant. Pin Flip Email. You need to input when you get your period so the app will learn your cycle, and tell you when you're most likely to be ovulating. However, pregnancy can still happen. Here's eight myths about periods we need to stop spreading. Why Is My Period Late: However, pregnancy can still happen. Some women will experience premenstrual syndrome PMS symptoms as pregnancy symptoms, where other women do not typically have these symptoms every cycle. Fears or hopes of getting pregnant can be an emotional roller coaster. In an average day menstrual cycle, ovulation typically occurs about 14 days before the start of the next menstrual period.