What Causes Cramps In Pelvic Region And Uterine Ache During Pregnancy?

Hi, I m 27 weeks pregnant. (5th pregnancy- no complications on any) Yesterday evening I had crampyness in my pelvic region, followed by overall uterine ache. I think I may have been having braxton hicks. Later after that passed my abdomen was sore down the central line and uncomfortable to walk. By night/this morning it is very painful from about top of the uterus to about 3 below my belly button in a path a couple inches wide. It is very sensitive to the touch and hurts like a muscle pull when I try to sit up or perform any activity engaging my core (including just walking). Is this just DS or something more? I ve never had this issue before, especially w/ such sudden onset. Thank you.