I Got The Bar On The 8th Of January 2016,

I got the bar on the 8th of January 2016, before that I was on the Estelle Pill for acne from June/July 2015 and stopped the pill the day before I got the bar (I took the pill constantly and didn't have a break for periods) I had sex for the first time on the 23rd of January 2015 and now I've had sex 23 times and its like a burning pain. he has no STDs and we used condoms and they didn't break but what could it be??