Possibly. It might be just because she's too big to lay on her tum anymore. If she's in labour...then chances are that by the time you get this then she will have given birth...if not....
You will notice her sides heaving with the contractions, and maybe a little watery fluid loss from the business end. She might pant a lot & the heaving will get more and more until she is actually pushing...then heypresto you get kittens.
If all is well there is rarely a need to intervene, only if she is in excessive distress, when it could mean that 1 of them has got wedged inside...but they seem to do amazingly well on their own.