Is it common for a mare to look 'swaybacked' in late pregnancy?

My mare is getting pretty close to foaling and her belly is getting big! I noticed yesterday that her back looks a TINY bit swayed. I'm not even sure if it should be called swayed--it's just a teeny tiny bit more dipped in than usual. I was wondering if this is common in pregnancy? This will be her 3rd foal. Will it ever go back to normal?

I'm not sure but my best guess would be she's losing top-line muscle during pregnancy due to lack of work.
I hope others can chime in because that's all I could think of lol

That would make sense! I'm pregnant too lol so I haven't been able to do much with her. I "hired" someone to come over and ride all of my horses for me until I'm able to, but she doesn't like the idea of working with her right now, since we are unsure of her "due date." We thought she would give birth this month, but since it's almost over, I guess not!

Hey I agree with xlioness. Freya went from full work to baby mumma and lost all her muscle. Just have a peak at my thread on her pregnancy and she really drops away from her back.
Put some photos up so we can see!
Freya's foaling thread

Yep totally normal especially if she's had more than one foal - it will come back with work and feed

Thanks so much, guys! I'm such a worry-wart these days xD