You can have morning sickness anytime within 9 months
A little off topic but how did your 20 month old do? Are they 16 months apart? I'm due in 44 days with my second and my son will be 16-17 months old when she's born and I'm super nervous!
My baby is just 10months and am 6 months pregnant. Feels very weird because I feel I might not pay enough attention to him again oonce the new baby is here.
I also will have 3 under 3 but only for a short time as my daughter will turn 3 when the baby will be almost one month old. I think it's normal to start nausea anytime during pregnancy unfortunately.. maybe it'll end earlier for you this time around? Either way, I think it's normal.