I spoke to a doc about something similar. He said. when a child is scared, they wet them selves. I am not calling you a child by any means. What i am trying to say is that when we are worried, we tend to tense muscles involuntary without realising that we are doing it. bladder spasams are a common outcome of this. You are now paying too much attention to it which in turn leads to more anxiety about it that in turn intensifies symptoms. try to relax, probably nothing to worry about. wont be an std in the real sense of the word but could be urethritis caused by normal mouth bacteria. sit tight for a week and see if it passes.
if you are still worried, see a doctor.
I red a quote that Dr Hansfield posted. It went something like this.
The more information given to a person, the more that person will diagnose plague when in fact he just has a common cold.
Urinating like that alone is not a stand alone sign of a STD. So while I doubt it is a STD, you should see a Dr.