Pain during working out

I’m 34+3 and I’ve tried to stay active through this pregnancy. Working out at least 3 days a week. Walking my dog every day sometimes twice a day. I’ve still gained like 45 lbs 😭😭😭

Anyway I was working out today and I got this pain in my lower left side of my belly. I was only about 25 min in but I stopped because every movement after that hurt.

The pain is still there. It’s not an excruciating pain more like a dull , lingering cramp.

Should I be concerned? I think today was my last day working out until baby comes.