Hi Rachael,
My problem was still happening months later - about 5-6 months postpartum I think when I consulted the GP about it!
If you are not breastfeeding I believe the hormones return to normal quicker. Breastfeeding keeps them lower for longer.
Of course, having a baby contributes - heaps physically!
I had a caesar so my problem was not vaginal birth related - it WAS hormonal! Something to do with the way hormones affect muscle tone! Things are much more normal now!
HTH
TICKLISH