PAINFUL low kicks/hits?

I tried googling but didn’t come up with much. I’m 37 weeks, so baby is fairly large and head down... the past few weeks ive noticed that occasionally I’ll feel movement below my bikini line, and it HURTS. I don’t know if he’s punching me or head butting me, but it literally stops me in my tracks and will bring me to tears if he doesn’t let up.

I know about lightning crotch, and that’s also just as painful, but I haven’t found much information about his movements being so painful in my lower uterus/bikini line area. I thought it would be round ligament pain, but it’s not just on the left or right, it’s the entire area covered by my underwear that’s extremely painful, wherever he hits down there.

Is anyone also experiencing this? (This is my first pregnancy btw