No matter what your first step should be to see your OB/GYN. He/she can properly diagnose whatever is going on with your body. Women can usually tell when something is different or "off'.' It's important to pay attention to the signs your body is giving you. If you're not ready yet to see the doctor, the internet can be a great resource but don't get caught up in it too much-- you might scare yourself into believing you have something you don't. I personally keep a copy of "Our Bodies, Ourselves" in my house and it is an incredible resource detailing almost anything and everything that goes on in our bodies. Until you know what's wrong, you sholuldn't take any action: you could potentially make the problem worse. In good news, many STDs can be treated with antibiotics or managed enough so that you can live a full life. My best advice- GO TO THE DOCTOR, preferably one you trust and was well referenced.