Pain when peeing and peeing often?!

I've been having a burning feeling in my vagina and I've had to go to the bathroom very frequently. I just finished my period not long ago. I'm on the pill and my boyfriend finished inside me before we went to the pool. It's only been a couple days. Also there's spotting and I've only been on the pill for about 1 and a half months. Do I have an infection? Is this something that just happens and will pass?