What is morning sickness like ?

So I know this is a weird and probably hard to answer question but what is morning sickness , like is there any way to really tell the difference between it and other things like acid reflux and just being sick ?

I’m around 7dpo but could be 12 or more I really don’t know for sure cause I don’t use opks I just go off cramps spotting and cm and the past two days about an hour after I get of work I’ll randomly get the urge to puke like a knot forms in my throat and it’s bright yellow and sometimes foamy it’s absolutely vile like throwing up sour lemonade and then I’m fine till the middle of the night and I wake up with the knot again I’ve never had acid reflux before so it could be that and I just don’t know for sure . Any opinions will be appreciated. Sending baby dust to us all 👶🏻✨💕