Since we cannot diagnose or test the problem, you need to see a doctor for this. The will most likely have to test/culture this "bump" to see what it is before they can treat it.
In the meantime, do not go without unprotected sex. Until you know what this problem is, do not have any sex of any kind.
Yeah but i'm just wondering.. what does it look like? :s
I do not know what it is (it could be several things), but without a direct examination, which I cannot do here on the forum, and testing, we cannot diagnose. That is why you need to see a doctor.