Showing already?I am so tired.?

I found out I am pregnant, 8wks 6days. I have been sick so much, I had a cold then the flew. I am not hungry but eat a bite at a time utherwise I throw up. I have major headaches. I have a three year old daughter and it was an easy pregnancy besides her trying to come out earlie.Even though I have lost 6lb. in 2 wks I still feel like my stomach is pooching out there. I have talked to my obg and we are doing an ultrasound the 13. I am sooo tired I could sleep all day and night. Everything reeks, even the air outside- has the world turned in to an armpitt.. I am wiried I am carying twins it runs in the family and I am next-we will find out at the ultrasound. How could I be showing already and why am I so whiped?