I have had uti symptoms for about a week and so last week I gave a sample to the GP and she gave me trimethoprim 3 day course. The sample had white blood cells on dipstick but the culture came back normal. I was feeling unwell/worse at the weekend and so out of hours gave me a 7 day course of cefalexin. I have taken 2 days worth of these so far and the pain is improving but still have urgency and sore bladder etc - how long should it take for an improvement/when should I contact the gp? I’m quite confused about the negative culture!