I've had chlamydia twice, maybe. Once for sure, and once maybe as a false positive (I had tested negative two or three times since the positive/treatment, and all of my partners since my last test but one tested negative; he still needs to get a test to be sure, but I tested negative in my throat, and I find it hard to believe that we could have tons of unprotected oral but vigilantly protected vaginal, and yet I could catch chlamydia in my vag but not my throat from him). It's no big deal, honestly--one pill and no sex for a week. I wasn't symptomatic either time, though the first/for sure time I felt a little off and had what I thought was the flu a bit earlier, which can actually be chlamydia taking hold. The second round, none of that, but I went for tests because I thought I might have been exposed, and got treated, but the guy whose other partner was positive came up negative himself twice (and I physically saw those results)... so, either it's a false positive, or a weird mystery that I nuked out of existence anyways. I was about to get my period at the time, so who knows if that affected it (I was barely spotting but enough that she treated me for gonorrhea as well because my discharge was slightly brown up by my cervix--came back negative for that, though, so I got a shot in the butt for nothing).

I only know about trich as an STI because one time at Planned Parenthood while I was there for an annual, they asked if they could do extra swabs for trich testing for research, and I got forty bucks out of it. Because hey, I was already getting swabbed, why not get swabbed eight more times while I was at it?

For the record, I'm ethically nonmonogamous. All my partners know I'm seeing other people, and are seeing other people themselves, and we all use protection. For vaginal, anyways. But that's why I get regularly tested. Even when I've been monogamous I get tested once or twice a year. Nonmonogamous, I try for every three months or so, with an immediate visit if there's some reason to worry (like the possible exposure, or that time I was dumb and went bareback in a car while traveling for work). Condoms aren't perfect, they just help, so, vigilance.