Blood test

My period isnt due for another 2 days but for the last week I have been nauseous and everytime I eat i throw it back up. I took a test and it was negative, but alot of people told me their test didn't come out positive until after missed period. Im freaking miserable, I haven't ate in 3 days because most of the time the smell of food just makes me sick. So my question is if I go to the doctor do you think they will do a blood test to see if im pregnant since im still early?