Cramps!! :-( heating pad??

I have been having cramps that come and go throughout the day for about a week now. It's so aggravating and uncomfortable because I feel it in my lower abdomen, back, and even down towards my bottom. No bleeding though.. It wakes me at night and I apply a heating pad to it.. It does help but I try not to use it because Im not sure if it's safe. I think im about 5 weeks. I havent had my 1st appointment yet. Does.anyone else experience this and is it okay to use a heating pad on the lower abdomen at 5 weeks?