Burning sensation. Reason for this?

I am 24 year old female, I am  having a mild  burning sensation in my genital/ vagina  or Urethra I am not very sure where it is . I don't have any symptoms like frequent urination or pain during or after urination , difficulty in urnination etc.which usually happens in case of UTI . Sometimes I feel there is some tickling feeling down there after 3-4 minutes after urination. The burning sensation is usually at specific times of the day and then it vanishes. Especially since it's from 10 am to 3 pm  after 1-2 nd urination  after which I don't feel any burning in that area. I don't have any other symptoms apart from this burning sensation at specific times. No pain / swelling / abnormal discharge from that area . I am not sexually active as well . My menstrual cycle is starting this week and it has started as well today but this issue is happening from last Friday. I have a regular menstrual cycle. A week back I have been out of station . What could be the possible reason for this ?