It could be an std of some kind. You should really get yourself checked out, screened for everything. If you go to planned parenthood or a family planning clinic or even your family doctor it is confidential and you can get full std screening and an exam.
I know it's uncomfortable but it's important for your health. Also, when you're ready for a sexual relationship with someone in the future, it's important to know that you aren't going to pass anything along to someone you love/care about.
Some of the most common std's have no symptoms but can cause permanent damage (fertility damage) if left untreated. Chlamydia is an example of one that is extremely common, very often has no symptoms, very easy to treat/cure but can cause serious (fertility) damage if left untreated.
If you're nervous about going alone maybe a close friend will go with you.