Hi c.shallow, I am 15 weeks pregnant with my first and at week 6 I also had pains in my tummy - they were very similar to period painsif that helps. My GP said that these pains were normal and that is was probably baby getting comfy and settling into the womb, it could also be that your womb is stretching to begin accommodating baby.
I was still pretty panicked when I had my bloods done so mentioned it to the nurse and she really made me feel better, she said "Have you had an ectopic pregnancy before?", I told her no and she said, "Well in that case, trust me, you would definitely know the difference between what could be a normal, pregnancy pain to an abnormal, "bad" pain". I think she meant just not to worry and to trust my instincts; if the pains become painful (unbearably or worryingly so) then contact your gp midwife, but otherwise it is probably just your body adjusting.
Congratulations x x x