Sounds like ligament stretching. It doesn't feel pleasant but is normal.
It's true - the ligaments are stretching so they can support your growing uterus. You'll continue to feel this off and on. You should only be concerned when they last for hours upon end - then call your doctor! Also, in a few weeks your uterus will start running contraction tests to practice for delivery. Again, not too painful but just a new feeling. Our bodies are amazing!
hi hun its nothing to worry about its just eveything down ther streching congrats