Throwing up for several days

Ok so I'm not sure what's going on with Kate. She threw up right before bed on Thursday night and when I say throw up, I mean projectile and so much it soaked both of us. Then she was normal and drank her bottles until Friday at 2:30 she threw up again. Yesterday, she only had one full bottle and only ate 2-3 oz every other feeding. And it seemed like she was not going to throw up again until midnight it happened again. She is very smiley and happy, no fever, and no diarrhea. I'm just not sure it's a virus. This is also the 2nd time this has happened. I'm probably taking her to the doctor tomorrow but does anyone have any idea what it could be?