Baby bump stuff

At what week/month did you notice your belly button starting to change/pop out (does it always?) and when did you first notice belly stretch marks?

I’m finally starting to have a little tum at 18 weeks, and while I know everyone moves at different rates, everything I read is telling me I should have itchy tummy already and I definitely don’t. Lol just curious what everyone’s experiences were!

I feel like I need to edit for clarity: for those who DID get stretch marks, at what point did you notice them starting?

I understand how stretch marks/genetics work. Thank you to those who are responding with their personal experiences, whatever they may be! (And I don’t mean this to sound rude! I just am looking for a specific question to be answered)