a little paranoid, second time I had sex help??

okay so im 17 and my boyfriend and I had sex for the first time 2 weeks ago a day after my period stopped, and the second time was 2 days ago and the fertility window was high. Both times were with a condom but because it's my first few times i'm just a little paranoid and i feel like i may be pregnant but maybe that's just the paranoia, my next period starts on  September the 30th. when will i know if i am pregnant or not? the paranoia is killing me help