Morning sickness is back at 12+4

Michelle • 33 year old from Australia , currently pregnant with baby #4 a boy..miss 7 mr 5 miss 1 and prince due 26/01/17
So I was suffering bad ms till 10+ weeks on meds daily to help then all of a sudden it stopped , I assumed since the placenta took over that why it stoped , well yesterday and today it's back with a vengeance :// this happen to anyone else and it stop again ?