Hi, did you have unprotected sex? Most likely your period is just late because if you did have unprotected sex, home pregnancy tests are very accurate. They pick up the hormones a pregnancy produces and if you don't have those hormones, you're not pregnant. Periods can be late for a variety of reasons including stress, changes in routine, weight gain or loss, thyroid issues, hormone issues, etc. My period for about a year or so came every 3 to 4 months! My thyroid was slow and I was naturally producing too much estrogen which resolved on its own. If you go a full three months without a period, you should check in with your doctor to determine a cause. But it doesn't have to do anything with pregnancy. good luck