Did I screw up my chances with this girl?

[Happy Guy]

Theres this girl in class that I LIKE. I saw her looking at me a couple of times but I dont know if it was out of interest or if it was just because she looks around the class, because at times she seems out of it. but I Like her. I decided to man up and walked up to her and said hi when is your birthday, then I said do you have a facebook I could hit you up in case I am absent and need the work?
She said she forgot her facebook and instead gave me her email.
Did I f up by just saying I want it for in case im absent? which isnt the truth.
this is a college class. i only see her 2 times a week