I am having the same symptoms. I had a miscarriage in August 2013, and the cramps give me the fear it's going to happe again. This time it's nothing like the paim with miscarriage though. It seems to come and go, switch from side to side, and stay mild. Still so scary. I can't relax.
I'm glad to have found this question because I was wondering the same thing! I'm 5 weeks and I've had them for the last two weeks on and off. Glad to know it's normal :)
I have had them off and on, sometimes really painful, since week 3. I think it's normal as long as you don't have any bright red bleeding. I take a Tylenol when it's really bad. I hate them because it feels like my period is starting and worries me. But I'm trying to keep calm. It's just our Uterus growing.
I've been thinking the same thing!