Progesterone 10 day prescription

I stopped the pill in October and haven’t had a period since. I had an obgyn appointment Friday and my cervix looks great. I feel like I have PCOS and we discussed it briefly. I was told I would come back in 3 weeks for an ultrasound. He prescribed me medroxyprogesterone and to to take one for 10 days and I should start my period. I’ve had a creamy discharge for a couple of days. This afternoon I took my first progesterone pill and am crampy. Is that normal?