I felt the same thing! And I didn’t experience it with my first. Idk if it was the food I ate prior to it happening or if it was Braxton hicks. I’m 21 weeks.
It’s normal. I had them too and spoke with my gynaecologist. Apparently it’s just the muscles preparing more room for the baby. It’s my second pregnancy as well.
I'm 21 weeks Thursday I'll b 22 pregnant with twins and every night I contract really bad make sure to drink alot of water so it goes away!