Well I always get flak for this but here I go again... Yes, the risks of STDs, especially the serious incurables like HepC and HIV, are vastly overstated. I understand why, it's a complicated subject and the nuance and responsibility are beyond most people, so from a public health perspective its better to keep things simple. But the reality is, under certain circumstances, especially for men, the transmission risk is on par with other deadly things that can and do happen, but almost nobody alters their behavior to avoid, car accidents for example. The transmission risk of an asymptomatic female to a male with no breaks in the skin on or near the penis, during well lubricated vaginal sex, of barrier-preventable disease (and an order of magnitude more so for hep/hiv) is statistically negligible compared to the normal daily risks of mortality or permanent disability. Yes, lots of caveats there, and the risk goes up quick with each deviation from them, and certainly most people wouldn't know an std sign from razor burn.. But I refuse to wear condoms and don't generally get with "nice girls", so I looked into just how much risk I was putting myself in. Turns out not much. Not enough to justify avoiding sex instead of managing the serious risk factors. Its not just luck that 15 years of sex with almost exclusively girls who were fellow IDUs or other addicts who took no precautions with their many other partners or, ahem, trading partners, has resulted in no infections for me (yes, I get tested).
Regarding pregnancy, girls can't actually get pregnant from precum, so between pull out and rythym, perfect use (again, NOT easy, and not achieved by most who try) is similarly low risk... Although now in my 30s that's no longer a concern beyond respecting the girls wishes since I'd welcome a child.
Sex with a condom is not sex worth having. Even when you're with girls selling it professionally (who, by the way, accept a recent clean test and extra payment in lieu of a condom at 2/3rd of the time), or as amateurs with acquaintances directly for drugs (where I've never met one who even cared after initally being told). Even if something happened tomorrow... Once in 15 years? Life is too short. I'd never put a future partner at risk so that would curtail things, but I wouldn't have any regrets.