bhuntekaji bro, 

it is normal alien number generally called "A" is unique identification number which is only given to immigrant since you are non-immigrant, i.e. F1 visa is non immigrant visa , they don't issue "a" number and they don't require fingerprint for your ear card ..

your ear is  like this and it is issued to non immigrant 

while certain non immigrant get ear with finger print based on marriage, asylum they have "A" number and there sad looks like this :=

i hope this info works for u ,,,,,