Terrible cramping

Hi everyone, I have been cramping throughout my pregnancy thus far. 6w2d today. Sunday and Monday I had a bought of really bad cramps that wouldn’t stop. Went and got an early ultrasound Tuesday and saw the heartbeat. My HCG is still raising. Was over 12,000 Monday. Over 30,000 today. My cramping is back again and it’s just awful. Did anyone else experience this with a healthy pregnancy? How can I tell the difference between normal growing pains/constipation. I’ve had 3 prior miscarriages and I’m just so terrified....but the tests say everything is fine....but the pain....