I've been getting that too (almost 6 weeks pregnant).

I went to emergency, had blood tests and ultrasound and more blood tests to check hGC levels and make sure that the baby is in the uterus. The pains have gone now and it was probably just my uterus growing. They told me to come back if I start bleeding (which I haven't) or if the pain gets unbearable (which it hasn't). I think it was just normal. But even if it is nothing, if you are concerned, go and get it checked out just to put your mind at ease. It's better to be safe than sorry.