My favourite example is when both my ex and I got identical inner ear infections after walking home in a stiff wind. He went to a clinic, got his ear flushed out, and was prescribed antibiotics.
I went to a different clinic, and explained I had vertigo and pain in my right ear only. I also mentioned I'd had recurring ear infections since childhood, and this felt like an inner ear infection.
The doctor said he couldn't see any discharge. Well, you often don't with inner ear infections.
His conclusion, even after I mentioned my partner had the exact same thing, was that I was pregnant and in denial about it. He said I'd have to stop taking the Pill and get a pregnancy test done after waiting a month. I asked since when was vertigo in one ear only a symptom of pregnancy and we argued until he basically dismissed me.
Further to that: at this point sometimes when I'm telling this story, people ask if I wound up having a miscarriage.
I WASN'T PREGNANT.
But I was sick, and it took me weeks to recover while my ex was back to good health after completing the course of antibiotics. I was a casual contractor working hourly then, my ex was doing short-term contracts, and I couldn't afford to take any more time off work.
So I warned my students if I sat down suddenly it was just another vertigo attack, and worked while sick.
To this day I have chronic ear and sinus issues on that side, although it's better than it used to be. GPs always say they can't see anything wrong, but my dentist notices. Last week I had a root canal on that side. The tooth had been killed by infections.
The ability to become pregnant, even though I never have been, has cost me thousands of dollars in dental work, sick days, and all the crap that comes with chronic illness.
ETA: my ex didn't have any discharge either. The difference is they believed him when he reported his symptoms.