i fucked up

so i hooked up with this guy 2 nights ago and now i cant stop thinking about the possibility of being pregnant. we did use a condom, so can you all please help me ease my mind..lol! i feel like an idiot! im so worried about catching an std and ending up pregnant... please tell me im over thinking this!!!! im soo worried because im going thru a divorce and have a 5 month old baby already. . :/ and THIS guy is a loser with 2 kids he doesnt see already. (no judging plz, it was a huge mistake) god i feel so stupid...i hate myself right now. Ugh!