My doctor started me on progesterone i got my first period since last night and i am having extreme cramping! with very light flow! in a lot of pain?

Progesterone: Limited information. How long have you been on progesterone and for what reason? Hormonal therapy can have a number of effects,cramping or PMS like symptoms is one of the possible effects ( even though it is usually a muscle relaxant). Have you tried motrin /ibuprophen or alevle ( if not allergic)? Would follow up with your doctor in the AM.