Pregnancy systems on 2nd?

Ok ladies! I have a 2yr old boy at home and the last 4 days or so i have been feeling pretty sick. I didn't get morning sicknes with my son but it wasn't until about 10+ weeks in. I've taken 2 home pregnancy tests over the last 3 weeks but they both came back negative. I have to eat every so many hours or i get sick. i did miss my period and have been having some of the same symptoms.

my question is, can you start gettting sick before registering a poisitive on a HPT???? i'm going to the dr at 2:30 to have them test me.