I had a lot of cramping with my second pregnancy and the doctor said its because my body remembers the first pregnancy and prepares for this one early and the cramping is all the muscles and ligaments stretching.
I had cramping with both pregnancies until about week 13. I'm 17 weeks now with #2 and I'll still get the occasional cramp. As long as there's no blood, you should be fine.
This is my second pregnancy but with my first i never had cramping there isn't any bloody show or nothing like that
If it's your first pregnancy then it can be from your uterus stretching. As long as the cramps are not followed with spotting or bleeding you should be good to go. Make sure you are drinking plenty of water....when I don't drink enough water I start to have cramp like feelings even at an early stage.