Strange irritation in my Vagina?

The last couple of months I've been experiencing a strange irritation in my vagina, it's hard to explain how it feels but the closest thing I can say it feels like is burning but it's always triggered by peeing in the morning, and my pee is slightly off colour as well but I drink plenty of water. I've been to the doctors about it and she did an exam, she did a high vaginal swab, a chlamydia test and a urine sample and they all came back normal! And sex is very uncomfortable too :( Any suggestions?