i know we were safe, but i cant help be worried...

hey everyone,
so the jist of it is i was with my boyfriend the other weekend and we had sex a few times. he used a trojan condom every time and even pulled out well before he came. i know we were safe, but i cant help but still be worried about being pregnant. my next period isnt until around the end of the first week of every month (about 2 1/2 weeks away). I've heard that stressin out too much can cause you to miss your period, and "feel" symptoms that arent really there.

So my question is: am i just being too paranoid for my own good? or do i need to be worried?

Please serious answers only, ASAP!