My dog fell on its back and now she can't move her tail?

So, our 6 year old pug was on our master bed. We have another pug who was on the bed too and she got jealous of the other and started a fight. She knocked her off the bed and she landed on her back. Now she is walking around but her tail is just limp between her legs hanging back and forth, so far I haven't seen her curl it up or wag it. The fall off the bed was around 2 - 2 1/2 feet. Is this something serious and should we take her to the vet? She hasn't shown signs of distress so far, but it only happened around a half an hour ago.