Looking up during prayer out of instinct,

As I am a student, I pray dhur in school during my break (pretty short) During my prayer today, I heard the sound of what I thought was either a bird or a rat which made me look up front (not at the rooftop though and for a second) (I think by instinct since I got scared). I was already late to my class so I couldn't restart my prayer again, is my prayer valid? If not, can I redo it?