I am on an contraceptive pill for for 4 months already and since then I had a pimple outbreak. So I decided to change my pills to diane pills even though I'm not checking with my OB for this matter. I followed the instructions i read carefully on the package, but I was wondering why i haven't had my period until now. i'm always on a regular cycle for my period and I had a negative result for taking pregnancy test. How will I go about this?