Hi I had this in my first pregnancy at about 6 weeks. I didnt actually believe I was pregnant as I thought my period would come at any time now. When I did the test I was surprized! I think it is quite common, and I am now pregnant with number 2 (16wks) but havent had anything this time. Every pregnant is different so try not to worry. If you have any bleeding at all, I would get it checked out - I did on a couple of occasions but turned out to be nothing, so again dont panic if you do. Good luck!
Where are the pains? if they were to be attributed to anything in the womb they'd be very low down behind/around your pelvis. If they're any higher up, it's most likely something stomach/bowel related (probably wind or diarrhea)
Have you been eating lots of fibre or fruit? I say this because I ate a lot of dried fruit a few weeks ago and had similar pain (accompanied by spotting) which led to me having an early scan, but all was fine. And then I had horrendous wind!
I had awful cramps at around the 6/7 weeks stage with this pg (my second). Like you, I'm sure I didn't have it with the first. And I haven't been overdoing it on the dried fruit . I did get an early scan as I was worried - the pains were so bad they'd wake me up in the night - but everything was fine. Just things stretching again, I think.
I had these cramps from week 4-8 and it was just like I was going to come on at any moment. I went to the docs and she said it was my womb growing and things starting to stretch/move. I also experienced two small bleeds and had a scan to check everything was ok and luckily it was. It's all so scary so I feel for you completely. I'm sure everything will be fine and it's just the old dried fruit overdose!