They don't expect you to know.
It's just an opener. They want to talk.
there's just LOADS of threads on here that are exactly the same.
Anything at all that asks where can I get such and such, or what's this or how's that is very easily found out by doing a simple google search. So why do people bother to ask questions that they can easily find the answers to in about 5 seconds on google?
The point is not to get the information, it's to talk.
In many cases, what they are talking about is irrelevant. Like rl small talk, it's about the social interaction.
Or guess what happened to me today or what's for dinner or hey, what do you think of this dress, etc etc.
So when someone says am I pregnant, they know nobody knows - they just want to talk, want a bit of attention, yes, but is that so bad? - why are any of us here?
I'm here because I want attention and interaction. I want to connect with people. I wouldn't be typing stuff on here if I didn't. I'd shut up, log off, get a coffee and go watch tv or something.