What is this pain? Braxton Hicks? Round ligament? Gas?

Be

So I’m 28 weeks FTM, and haven’t had too much discomfort this pregnancy so for (or at least nothing out of the ordinary) but last night I woke up in so much pain! It was underneath my bellybutton, the span ranged from hip to hip with a bit of tightening in the front center above my bellybutton. It lasted about 20-30 minutes and at first I thought it was gas pain, but there was something different. More like a really bad menstrual cramp - like the kind that makes you a bit dizzy. The only relief I got was when I laid on my back, concentrated on breathing, and tried to stretch my knees to my chest. After a while it all of a sudden it stopped.

I was thinking it might’ve been a Braxton Hicks, but aren’t they not that painful? And don’t they only last a few minutes???

Does anybody have any idea? And should I be worried?