Definitely get it checked out. It could be a rolled rib. I get them in pregnancy, as all my bones seem to want to wander off in other directions. It's excruciating, but chiro helps. Do you know bub's position? I had it constantly with DS1 and it turns out his head was stuck under a rib, pushing it out of alignment.
That sounds delightful L&B! Bubs is head down, bum to the left and feet to the right. I hope she hasn't moved, doesn't feel like she has. I hope it eases, struggling today