one night me and my boyfriend were drunk and it was about the middle of the month for me and we had sex but he pulled out. Now i am freaking out becuase my period is 4 days late and i have never ever been late before but always early or right on schedule. i no it might be due to stress but i have been extremely stressed out many times and i still have a regular period. I have taken two pregnancy test, one two days before my missed period and one just yesterday and they both say negative. should i trust this and just believe that it is stress?? please help i am stressing about this so bad! :'(