Can tramadol cause a false positive on a urine test

How could the doctor tell that she was having twins based on a urine pregnancy test?

How many LW stories involve a guy getting a positive STD test or a DNA test that shows one of his children aren't his, and immediately getting started on closing bank accounts and seeing a lawyer?
It's not like "Let me immediately take action based on belief in the complete accuracy of a single medical report" isn't the norm in such stories. Arguably, her real fault wasn't in sleeping around, it was in going home and thinking there was going to be a marriage left after she blew it up.
(And, to be honest, I'm sure many of the readers don't actually understand how false positives work. If you get a positive result on a 99% accurate test, that doesn't mean there's only a 1% chance of it being wrong.
On rare diseases, a positive result is very likely to be a false one, simply by the weight of numbers: If a test is 99% accurate, and 100,000 people get tested for a disease that only 500 of them have, then you're going to end up with 495 true positive results (99% of the sick people got accurate results) and 995 false positive results (1% of the healthy people got inaccurate results). In case like this, that would mean that a positive result in a 99% accurate test is only actually a ~33% chance that you have the disease.
tl;dr: The doctor was an idiot, and the ending should have included a malpractice lawsuit for failing basic math.)

Ohhh. Deep fakes. Ever more, one-time sci-fi becomes standard in LW stories. I expect more deep fakes going forward, including true fakes (as in the spouse us innocent). These are already showing up on social media, and there have been LW stories where faked photos blew up a marriage (hell, I wrote a story where a false-positive HIV test led to revenge sex--the title is Positive, if you're interested).