Your GP should have sent the sample to a Lab., there are too many ABs being prescribed 'in case'. If the sample doesn't grow any bugs then the patient does not need ABs, but appropriate treatment. If your GP thinks there is an embedded infection, this needs proper diagnosis by a Consultant and treatment. I suggest that you ring to find out which Lab it was sent to.
Take some 'nurofen' which will ease the feeling of a need to pee. Buscopan is for indigestion. We used to give it to my dog who had a slight twist in the gut occasionally, he would have two tablets then burp about 20 mins. later.