Is bleeding normal after you get your retainers?

Ok so, I got my braces off yesterday(yay!!)) And at first, my retainers felt fine, of course pressure but fine. Today, I noticed how sensitive my lower gum was but thought that it was agitated from the retainer. When I took off my lower retainer, I noticed my gum was bleeding and had bled earlier in the day too. Again, same thing tonight..