Period pains

Usually my cramps are in my mid abdomen area and are extremely painful, but feel more like a dull throbbing. I just started my period today and my pain is much lower and feels very sharp. It seems to hurt more when I walk too. Has anyone else experienced this? Should I be worried? My periods have always been very heavy, painful, and erratic so they put me on birth control and I’ve been on this pill for about a year now.