I have a single bump on my vagina...?

So one night i was completely fine and the next morning i woke up and when i went to pee i saw one single lump on the outside of my vagina. It hurts if I push it or squeeze it and so far I've had it for one day. What on earth could it be? It is a std of some sort? It's just one and it looks kind of like a pimple but not exactly because its popping out.

Help.

And please don't just tell me to go to the doctor I made an appointment for Monday.