Hair loss?

So my second child just turned 4 months on the 10th and about a week and a half ago I noticed a lot of hair on my hair elastic when is take it out... I summed this up to just being from having my hair up more than usual but it still hasn't really stopped. I know we naturally lose 100-500 hairs a day but idk if I'm just over thinking it (which I tend to do about everything... Hypochondriac if u will lol) but after my shower tonight my hair just feels thinner all together and it's freaking me out!!! Is it normal to have hair loss after pregnancy?