my parakeet won't get on my finger!

Hi. i got a parakeet about a month ago and he still won't sit on my finger! i got him at this pet store that had 4 locally bred parakeets and they were hand fed and everything. there was a sign that said they were 6-8 week old. i picked one out and the lady there put him on my finger. he was so cute! after that, i bought him and took him home. we didn't have a cage yet, so i put him in this small little pet carrier thing.

i tried to put him on my finger at first but he wouldn't get on. after an hour or two i tried again and he got on! some times it was hard to get him off beacuse he wanted to stay on my hand so much!:) then the next day, he wouldn't get on my finger, so it was a little hard to get him into his new cage.( i put him in his new cage the 2nd day i had him.) he still won't get on my finger and he is probably 3-4 months old now. sometimes he will try to bite me and i'm slightly under the impression that he hates me.

i also give him good food, water and toys. i don't think he's sick or anything. please help me! this is my first bird! what am i doing wrong and what should i do so he is happy and sits on my finger?