Hi, I have been on Fluoxetine for maybe 2 months . Each time my period has come late . I am also on birth control, which I have been for about 3 years now . I'm really starting to stress and go crazy . I haven't had sex in almost 2 months but my period came last month. I will hopefully be able to get a test . But my boyfriend CLAIMS he didn't "go" in me . So does it usually cause you to not be on your period ? ALL ANSWERS ARE VERY MUCH APPRECIATED !!! Thanks !