When did your nausea start?

And did it vary by pregnancy if you've had multiple? I'm 6 weeks today with my 4th pregnancy (1 living child), and don't have any nausea yet. With the first 2 I started getting nausea about now and it always got pretty bad. I had a miscarriage with my last one at 6 weeks, so never got it. Of course this is causing me to worry that it hasn't kicked in yet.

I had my first ultrasound 2 days ago and they saw a gestational sac and yolk sac. My hcg was still rising appropriately and I had my first dye stealer test this morning. So not sure why this nausea is taking longer, unless of course something is wrong 😟.