Help!!!

Okay for the last month I have been experiencing a burning sensation at random times whether it be after i pee or if I’m holding my pee. Which yes I know isn’t the best to do but sometimes I have to. I have been to my obgyn where they did bloodwork and urine samples and I was completely clean, no stds, no uti. I’m super confused as to what this could be. I’m unsure if anyone else has experienced this but I’m really running into a wall on this one.