TMI, but does this go away after birth?

I am 39 weeks pregnant, and for the last several weeks, my vagina, and the insides of my legs, where your leg meets your vagina, are EXTREMELY sore. It’s almost debilitating sometimes. It hurts to roll over in bed, walk very far, spread my legs, put on pants... you get the idea. It’s horrible.

I had an ultrasound to check on babys fluids last week, and she’s measuring 9 pounds & 42 weeks. 😳 could this be why I’m in so much pain?? Also, has anyone else felt this way? And how soon after birth does it go away?! I’m having a csection, if it changes anything.