I know for me when I switched pill brands my cycle went haywire then slowly went back to normal. M docotor explained that as your body adjusts to the hormones your cycle may change for approx 3 months until it regulates itself. However, I would still contact my doctor to make sure everything is ok and that that is the cause. Good luck
I've heard it can take 3-6 months for a cycle to regulate. Depends on the person. If you are that concerned go to an OBGYN not your regular dr. and tell them about your concerns. I too have VERY painful periods (only pain pills get rid of the pain, but they won't prescribe them for it. I lay around for a week or more as symptoms start 2 weeks before, and I can't DO anything, even work!), even the pill didn't work too well (10+ yrs ago haven't taken it since) I've recently been diagnosed with PCOS, but from what I hear that shouldn't have anything to do with painful periods. I'm debating on having a laproscopic surgery (camera inside me) to see if I actually have endometriosis as that DOES cause painful periods.