Bad HG in 1st not 2nd pregnancy??

Jade
Hi, 
My names Jade and I suffered terribly with HG in my first pregnancy, am still scarred from hospital stays, vomitting, weight loss etc, however..... Am now 5wks+3 with bump#2 and have no nausea at all! My understanding was if you have hg you ALWAYS have hg but I was terribly poorly by the time I got my bfp with my son last time yet I dont feel anything at all this time. Am still getting +ve tests and had no pain/bleeding etc so don't feel like I've miscarried but am concerned this isn't normal. Anyone not had hg with following pregnancies?? Am terrible for Google-ing things and had no positive stories on there 😩 . Any advice or input greatly appreciated!  X