See, I'm different... My pregnancies with my girls were pretty much the same. Severe ms til around 4.5 months, then eased off til around 7 months.
With DS ms was very minimal. I went from throwing up around 20 times a day some days with the girls, to maybe twice a day with DS. With DS I had SPD, but didn't with the girls.
All have the same father though.
I think it all just comes down to you & your body TBH