hmmm haven't experienced that myself in either pg, however its prob just your body adjusting/growing. The only cramps I've had have been in my legs/feet and annoyingly they only happen at night when I am asleep which wake me up- ouch! still its only every now and again so I suppose i can't complain
Hopefully your cramps stop soon, but if not, just call your OB's office and have a chat with them, as for nothing else, it'll give you piece of mind.