Im 12 weeks too acline :) I started feeling that pain early on and usually its just as celq said. However I see my Dr the 24th so Im still going to mention it to be on the safe side - prolly be a good idea for you too hun
I've experienced that kind of pain like period cramps kind of dull someone told me it could be just that you uterus is stretching because the baby is going through a growth spurt but always check with Ur Dr :-)
That's how it felt for me when I had round ligament pain.(: