D.K.
You didn't mention a THING about your diet or hydration levels. This can have EVERYTHING to do w/ the cramps. Cramps can be caused by dehydration. You need a minimum of your body weight in ounces (more if you're working out) in WATER daily.
If you are doing soda or coffee......STOP IT! caffeine is a diuretic.
Hopefully, you're taking a prenatal vitamin. Check the amount of calcium. Make sure it's adequate - NOT 25%. If it's not 100% or more of what you need, add a calcium supplement AT NIGHT. Your calcium needs to have magnesium and/or vitamin D in it. Might think about a chewable.
In addition, postassium is essential for muscle contraction. IF YOU ARE NOT GETTING ADEQUATE AMOUNTS OF POTASSIUM, this TOO may cause cramping. You prenatal should have some, but make SURE you'r diet is loaded w/ potassium rich foods.
Might want to purchase a copy of PRESCRIPTION FOR NUTRITIONAL HEALING by Balch. LOTS of user friendly info there!
In addition, since you've had a miscarriage, you'll HAVE TO GET A COPY OF PAIN FREE WOMEN by Pete Egoscue. This will take you thru EVERY trimester of pregnance and help keep your pelvis in position to handle the pregnancy AND keep you out of pain. Might even check AMAZON and Half Price book stores.