Cramps in 2nd trimester!?

Lily
So I am 21 weeks and have recently been starting to feel menstrual cramps and some stomach discomfort. I've researched and seen things about it being normal, Braxton hicks, or preterm labor, etc. mine are mildmenstrual  cramps but it does make me wonder. Anyone else around the same week as me feeling this? I'm not sure what it is. Of course I'll ask my doctor if I get too worried, I'm just curious about what you ladies are going through as far as abdominal pains/cramps. Thanks!