Is it normal to be only 4 weeks 5 days and have severe nausea and throwing up?

My last period was February 4th. I’ve heard to count 280 days from last period to estimate due date which puts my due date at November 23rd. Yesterday I got up felt severely dizzy and a couple hours later a big bout of nausea hit me and I just started puking.. like a lot. I thought morning sickness didn’t hit until 6 weeks or so. I’ll be a first time mom so don’t really know if that’s good or not.