About 2 months ago I started taking vitamins. My face started clearing up and my nails and hair started growing. Then I realized my periods started changing. My periods are usually very heavy the first 3 days and then light for 3 more days. Now my periods are just heavy three days and then I stop. Is that normal? My ovaries and back hurt after my period too. I feel pain in my lower ovaries. Is that normal? I'm sexually active but I'm always protected. I've never had a STD and I always get checked normally. Should I be concerned?