I started a new pill and i'm not taking a bleed (3rd pack.) i started w/light spotting 3 weeks ago&now have a reg period. it been 3 weeks&i'm worried.

Bleeding is common: If I understand correctly, you're not taking the placebo pills and trying to avoid a period. The usual result is that at some point you'll start to bleed. If that's the case, the solution is to stop the active pills for 4-5 days, let the period come, then re-start the pills. Bleeding while taking the active pills is called breakthrough bleeding. Your period is trying to come, let it.