Don't feel guilty about your behavior when you were younger. Nobody should be judged through life on the basis of how they behaved in their teens and early twenties-- not by themselves or by other people.
The rest of your follow-up questions continue the "where did it come from?" theme. I'm not going to try to sort it out and, as I said above, I suggest you don't either.
As for the infertility, the odds are in your favor. But as I said, this is an issue for your gynecologist.
Directly to your questions:
1) It is rare to carry chlamydia for more than a year or two; the longest documented case is 4 years. And chlamydia usually responds well to antibiotic treatment. Further, if you were infected since 2003, it wouldn't start causing symptoms now. Therefore, your current chlamydial infection is newly acquired infection, probably in the month before the symptoms started. A single brief episode of vaginal penetration seems low risk, but possible. You can't catch chlamydia through a properly used condom or by oral sex. However, repeated sex, even with condoms, leaves open the possibility of a lapse in condom use somewhere along the line; once is enough. Another possibility is that your most recent test was falsely positive. But that is rare with the currently used chlamydia tests; and your symptoms suggest the result was valid.
2) Your BF's test could have been negative because a) he had it but it cleared up before he was tested; or b) he was lucky and wasn't infected after you caught it in June; or c) he was infected but the test missed it. (I hope he was treated. That is essential, despite his negative test result.)
3) Every chlamydial infection in women carries some risk of infertility, and having 2 or more infections increases the risk. It is fairly unlikely in women who haven't had symptoms of infection extending into the Fallopian tubes (pelvic inflammatory disease, or PID), primarily lower abdominal pain. But there are no data to provide an estimate of the odds and there are no guarantees. This is an issue for your gynecologist. However, the usual advice is to simply try to conceive someday, and undergo testing for the cause if unusuccessful after a year of unprotected sex.
4) There has been no research on symptoms in chlamydial infection that goes untreated for long periods of time. Most likely symptoms can either persist or come and go.
I suggest not playing the "where did it come from?" game. You're probably never going to know for sure who was infected first and when. The important thing now is that you and your BF be treated.
Good luck--- HHH, MD
I guess what I am wondering about the March incident is could the burning sensation in the guy I slept with be unrelated to the Chlamydia? I just don't know enough about this stuff to know why else it may have stung when he was peeing.
I should have noted that my BF and I were monogomous that whole year - that's why i was confused about the potential positive.
Also, if I had contracted it in March, wouldn't I have given it to the friend I had sex with in May?
To be honest, my biggest concern is my fertility. I was a bit reckless during those college years and am now feeling so guilty. That is why I am trying to figure out this whole timeline issue.