*Nauseas* morning sickness

My nausea with my son was very mild.  
My daughter it hit me mostly in the afternoon- it was pretty rough with her. 
This baby it has started at 5 weeks G A and it has been anytime my stomach gets really empty or anytime I eat! It's like my stomach is churning inside. It feels like it does if you have a stomach virus but I haven't puked! 
It's also hitting me the worse around the afternoon after lunch and it comes and goes all day long Til bed!