So a few days ago my boyfriend and I had unprotected sex ... he didn't finish in me but on my chest, we have been very diligent about using withdrawal and contraceptives..I can't use condoms because I am allergic to latex... right before my period was about to start... 3 days before.... and I have been really stressed out lately about the chance of being pregnant. I took 3 tests and they were negative but I am 2 days late and it is really stressing me out. Please help... I am 19 and he is 22... I am about to leave for college soon and I am freaking out.

Could my stress be causing my period to be late?