last time i had sex was on june 13th, it was only the first few seconds unprotected and then he put a condom on. i got my period 9 days later and and in july i got my period again. my period is quite irregular, but I'm 8 days late. I've had some brown discharge, or spotting but no cramps or any other symptoms. is there any possibility that i could be pregnant or am i just stressing myself out? help