Tail wagging usually means a heat cycle. If she has discharge that may be why she is holding her tail down. Easiest way to tell would be to walk her near a buck! Also, what's the temperature outside? Mine will do this when it's windy and/or cold out too.
we got her temp last night--normal at 102. I did notice her vulva was very swollen and "poochy" so I guess she is in heat? Her tail also came up again later yesterday afternoon so I am gonna consider her "all good" for now thanks for the help!