Ouch!
Visits the obgyn monthly? Well, if she has to visit the obgyn monthly for std panels (kind of like what your positing is indicating), you have some issues to resolve.
First, you should not be having unprotected sex and risk infection from a woman who claims to be std-free. You are looking for problems and they will creep up on you.
I'm not trying to freak you out, but in my honest opinion you'll be seeing your doctor shortly. You need to run some tests because your penis is feeling some form of discomfort. Outstanding or slight pain doesn't mean no infection. Got it!
Great!
Now go to the doctor and run the tests. When everything comes back negative, change your sexual practices and protect yourself. Further, please protect the next woman who may innocently have gotten involved with you.
After week 13, please take an hiv test. Yes, an hiv test. Yes again, an hiv test. Yes again and again, an hiv test. This is because you put yourself in a very risky position. I don't care what the woman looks like, how many credentials she has, how many doctors she visits, nothing! You must not take a statement from a woman who claims to be std-free.
As a male, I think that it is our responsibility to wear protection. Forget the female, we should demonstrate the practice of safe sex. After marriage, and with full disclosure of medical records, unprotected sex is then an option, but you must be careful about pregnancy and the reality of producing a child.
Good luck, and get back to me!