Google and the way that pregnancy is spoken about in society are big drivers in this type of situation, rather than the younger generation lacking common sense.
Months ago I thought I might be pregnant. I couldn't/wouldn't talk to friends/family about it because DH and I had literally just started thinking about trying for a baby so I wanted to keep it quiet. The driving reason for that was the general consensus from older generations who already have kids that you'll probably have a miscarriage so should keep schtum. (I since don't care about this)
It was too early for me to test, so I turned to Google to put my mind at ease/get more info. But Google now forces you to have a shit ton of text on every web page (like when you want a pasta sauce recipe and you have to sit through 5 pages of the author's childhood in Italy and their thoughts on world war 3 before reaching the ingredients) - this meant that I was immediately overwhelmed and still didn't get any answers. I went through 20+ pages, still no useful info relevant to my situation.
So I went on Mumsnet, wrote the few symptoms I had and got the typical answer of "you're an idiot. Just do a test" "god people are so stupid nowadays, how should I know?". At that point, I didn't know that pregnancy symptoms can vary hugely, because every time you look it up, you get way too much info, 99% of which isn't even relevant.
I'm 28, the only place online I've ever been able to get consistent, short and snappy and useful information is on Tiktok and now that's being vilified and potentially banned. It's really difficult to research anything nowadays, let alone anything related to women's health. I'd say at least 90% of the common sense I have is due to Tiktok and hearing other people's opinions/perspectives/experiences and reading the comments on videos where people are disagreeing, providing more/different information, more context etc. We don't lack common sense, it's just really difficult to get your hands on it nowadays!