12 week confusion

So you know how they say when you get to two weeks you made it though the hardest part (in regards to most likely to miscarry) well I always thought that when you hit 12 weeks, BOOM second trimester. Nope I was wrong.

I’ve now learned it is when you hit 13 weeks but I’ve also been told it’s when you hit 14weeks?????

When the hell does it start then? Like I’m so confused why would they say the “danger zone” and make you feel like you made it to something when you haven’t?