I had the same problem at 5 weeks and went in for a transvaginal ultrasound. In my case it was cramping coming from an ovarian cyst that had ruptured (the fluid in my abdominal cavity was irritating my organs and causing the cramping, it eventually self-resolved as my body reabsorbed the fluid)...but what they also said, that I think you will find reassuring, is that it was too early for an ectopic pregnancy to rupture the fallopian tube (that kind of pain is excruciating and would typically present between 7 and 9 weeks). Getting checked out will be wise, but at this point - unless your symptoms change (e.g. bleeding, severe pain) I would really try to relax. It could be many things besides an ectopic pregnancy. Try to focus on positive things until you can talk to your doctor. I know I was really freaked out too - my heart goes out to you - but worrying will not help.