If you have any concerns, you need to call your doctor as soon as possible. While some cramping is normal, it's always better to be safe than sorry. Good luck and keep us posted.
This can be very normal because your uterus is working hard and growing to make room for baby! As long as you aren't having any bleeding things should be just fine! If you feel it's something to be concerned about, call your doctor and they can reassure you and check your out!
Good luck!