From a hairdresser's point, it is very normal. You caneither loose tons, or loose little. If your hair gets thicker during pregnancy than you may only loose a little and stay thicker. Which is what I do.
You may get thinner or dryer during pregnancy and not loose much.
So now you probably want to know WHY!
Loosing a bunch comes from the extra blood volume, extra vitamins, and extra protein intake. All which go to hair and nails. So you gain a ton while preggo. Well, about 3 months after when your hormones settle back into place, and your blood volume goes back to normal, it no longer has the support line to hold onto al the hair it created.
Going dry, brittle, or thinner is different. It may be a lack of cacium since pregnancy takes away TONS from your body. So taking an additional cacium tablet with your prenantal can help. Lack of cacium is also related to the thin brittle hair. Your body needs extra protein too and if your not geting enough, or getting enough of the vitamins and lipids that are needed for proteins to hang onto that can cause an issue.
So, dont always look at your conditioner when you are dry or brittle.
Hope that helps