What Causes A Post Coital Discharge With Itching And Slight Hematuria?

Hi, i'm 55 and a day or so after intercourse last time, i had a discharge that i thought was Thrush, as it was itchy.But this then became very slightly pink, and now after a week is quite watery very slightly blood stained. This is only when i urinate, or wipe myself, so not very much.I am on h.r.t and have been for 6 years. I haven't had a period for about 2 years, but have had a couple recently.