[Harmony♥]

Stressing can definitely make your period go off course. Even for women who have had their periods forever can easily have their cycles easily screwed up due to stress, changes in exercise and diet, and other things. Basically, ANYTHING can make your period go off whack, and because you're 15, it's normal for your period to still be adjusting to new cycles.

The first thing I'm going to tell you is to calm down and relax, and stop stressing about it. Stress DOES AND CAN make your period come early OR late. Freaking out about it isn't going to help, so the first step is going to be to sit back and relax, and stop stressing over the situation.

You mentioned that he pulled out and didn't cum. While the pull-out method isn't the greatest for birth control, it doesn't sound like these incidents have lead you to become pregnant.

When you took your pregnancy tests, were they two weeks after the unprotected sex occurred? If not, you need to WAIT two weeks after the incident before testing or you WILL have negative results on the test.