A.G.
It's very normal. I lost a ton of hair post partum, but it really didn't start for me until about three months post partum. For both of my kids it lasted until they were one or so, before it finally stopped. It is only because you do not shed very much hair while you are pregnant, so it just seems like a ton coming out (just built up over 9 months LOL). Everybody is different, but from my experience with clients it usually lasts 3-6 months.