Can pregnancy with progesterone supplement cause on and off, sometimes bad, period-like cramps in pregnancy after two miscarriages? There's no blood.

No. Progesterone relaxes your uterus where your baby is growing. It doe snot cause cramps. It can cause bloating and gas pains. Maybe that is what is confusing you. Take care. Drink lots of fluids and eat small portions and avoid gassy foods.