Hello. In all honesty, no one on the internet can tell you what is going on. There are times where we simply need to see a doctor. This is where you are at-- you need a doctor to examine this. If you don't have insurance, there is always planned parenthood where you pay cash and it is meant for indigent women who need help, so fees are low or an urgent care where they also have sliding fee scales often based on income and you can pay cash. If you are just embarrassed, then you can go to PP or urgent care for the same reason. Could be a cyst, boil, infected hair follicle, etc. or yes, an std. But it needs to be looked at. good luck
I meant i haven't had unprotected sex since then