I haven’t have sex in 2 months and no i’m not pregnant because every month i have to take a blood pregnancy test to insure i’m not pregnant since i’m taking my second round of accutane for my cystic acne, but i’m 4 days late on my period? Do you think my medication is making me miss my period or delaying it? Or cause sti’s/ std’s cause you to be late on your period too? I got checked 3 months ago and was fine. I’m just wondering what’s wrong and why my period is late.