Sick while pregnant

So last week I got some kind of Norovirus or something that made me super sick. I couldn't eat or drink on my own for 22 hours and I was constantly throwing up even while in the hospital with the IV for fluids and for Zofran. (Zofran is supposed to stop the throwing up) I threw up 27 times. Any who... they had to do a sonogram to check the baby. They said everything was fine. Scored 8/8. My dr called me last night, herself and asked me to come in for an emergency BPP. What is that and should I be nervous?