34 weeks and just got stretchmarks

I know this is vain, but this is my first pregnancy and I thought I was getting lucky. Today when I got out of the shower I noticed stretchmarks under my belly button from hip to hip. I cried. It wasn't there yesterday and literally came overnight. I know we are doing amazing things and of course I'm thankful that my baby is healthy and has made it this far, but just sad knowing my body is truly never going to be the same. My husband is reassuring, but between all of these third trimester symptoms and lack of sleep, this really got to me today.