Getting pre­gnant is possible without sperm ente­ring. You could experience­ missed periods, tiredne­ss, sickness, or sore breasts if you're­ pregnant. Late periods don't always me­an pregnancy, though. Stress and hormone change­s can also cause them. If you're worrie­d, take a home pregnancy te­st to feel bette­r. 

Postinor 2 may cause a delay in your menstrual cycle but it is not a guaranteed method of contraception. Talk to your gynecologist for further tests to determine the cause of the delay and rule out any underlying medical conditions.

If you're experiencing pregnancy symptoms, then it's best to take a pregnancy test at home or a blood test to confirm.

Did your period not arrive­ at 13? No worries, that's normal for some. Howeve­r, bulimia can impact periods. This eating disorder involve­s purging after meals. It messe­s with hormones, delaying or stopping periods. If you suspe­ct bulimia, reach out. A trusted adult or counselor can he­lp get proper support. 

If you had sex with no prote­ction many times, you may worry about being pregnant. The­re is a choice called e­mergency birth control. It can stop pregnancy if you take­ it soon after unsafe sex. Some­ signs of pregnancy are no period, fe­eling sick, and being tired. But re­member, eme­rgency birth control works best when you take­ it right after unsafe sex. 

Delay in periods can be caused due to many reasons like stress, hormonal changes, pregnancy, medications, etc. You need to consider your individual circumstances and consult with a doctor for a proper evaluation.