Its often difficult deciding if a vet's visit is necessary or not and its hard to advise what to do from a distance. If she's not in any evident pain, seems ok in herself and is eating normally, then I think I'd tend to wait a couple of days and see how it goes. However if any of her movements are restricted or she seems unhappy, then I'd get her checked out. It could be any number of things but if she's flinching or not wanting to put weight on her legs, then I'd get her checked out. Sorry not to be of more help, hope she's ok. Keep us posted!