I was having cramps at first too, and they could be pretty bad. But I usually have terrible cramps with AF, and they were no worse than that. They also went away if I put my feet up. Now at 7.5 weeks they really have almost totally gone away. From what I've read, you don't need to worry too much unless there is spotting. But if you are worried, a call to the doctor or midwife is well worth it just to calm your fears.
I initially felt like I couldn't call before my first appointment, but I finally broke down today and called because I was worried about an antibiotic my primary care dr. prescribed for this awful sinus infection I have. But they were very sweet, they called me back and spent time talking to me. Once you've made that appointment, you've hired them. Since they're in charge of your care, I think it's in their best interest to consult with you when you need them.