1 year old with stomach virus?!

My daughter is 18 months for 3 days she has not eating anything. She does drink her pedialyte and lots of water. She only threw up like once each day i notice when i really try to get her to eat.since the first night. She has no fever and I called and explained this to her doctor who scheduled an appt for tuesday but i am worried. I gone to er the first day and they said stomach virus but she still has not eaten in 3 days and seems tired she is not dehydrated and she is drinking lots but I am still so worried about my baby. anyone else go through this and if so... what should i do.