Hi I had the same problem and it turned out to be fine but you should have it checked out to make sure.

I am currently going through the same thing. Although I haven't had a positive pregnancy test yet. I am 5 days late, about 3 days ago I started getting some symptoms of pregnancy...Some say it is too early and some say it is possible. I have been having cramping, not normal monthly cramping, but more to one side. I was told that if you have an ectopic pregnancy, that you will feel pains primarily to one side. I was also told that ectopic pregnancies are commonly not detected by a pregnancy test. So for me, it is possible that I am having an ectopic pregnancy, getting the symptoms but am not able to produce enough of the hormone to create a positive test. For you, if you had a positive pregnancy test and are having those pains it could be stretching. Early in the pregnancy your body will start to adjust to make room for the new baby growing inside. Your ligements will start to stretch and your hips will move. So that is most likely what you are going through. I am no Dr. Though, I would recommend getting it checked out. There is nothing wrong with being overly cautious.
Sorry if I rambled...But I hope I got my point across either way.
Good luck and congratualtions!