Wierd Vaginal Symptoms

My boyfriend recently moved 12 hours away from where I live, so the periods between sexual activity are pretty lengthly. When I came to visit him yesterday, we had sex 2 times (not right after the other). After the second time I noticed a pain around the entrance to my vagina. It felt like a burning sensation when I went pee. I've had a UTI before, and I know that's not what it is. I have no inner pain, just on the outside. I checked it out to see if there were any cuts or anything, but I couldn't see anything. Today after I took a shower the pain began again. I didn't clean with any soaps or anything, just water, Could it be possible that I'm allergic to latex? If not, do you have any suggestions or tips?