It is not necessarily an STD (its possible, so you'll want to get tested). However, there are other possibilities. Look up another discussion on vaginal tears and you will see lots of other women with similar symptoms - and they don't have stds. If you're experiencing the pain and burning after sex, it could be severe irritation or vaginal tears.
you have cystitas.. u need to go to the doctors for antibiotics xx
if your feeling burning when you pee...thats not a good sign. it can be an std. you could have tore from the last time you had sex. it could be a number of things.
you need to go to the doctors get tested for all stds
im not sure about the K