Cramps and D&C

How long after your miscarriage started did you have cramps? Right now I am a week and a half out, still bad cramping that feels more like early labor pains, clear across my mid-back whenever I stand or walk. If they aren't gone by Monday I am supposed to call the dr to get and ultrasound and possibly a D&C. Also, has anyone ever gone against having a D&C (I was only 4w 4d when I miscarried) and just let their body go through another cycle to get rid of the tissue on their next period?