Severe cramping 4 days post d&c

I had a d&c; on Thursday and felt fine after the procedure. I've had minimal pain and very light spotting. Today I woke up and immediately was in the fetal position due to cramping. The cramping is below my belly button and above my pelvis. Sometimes the pain is more to the left. It feels like contractions in that it starts small and builds up to a high level of pain and then releases. It's stopped me in my tracks and brought me to my knees. I've taken some Tylenol and am waiting for it to kick in. Anyone else experience this before??