She doesn't feel like a girlfriend. we just have ?

i'm new to relationships but i just don't think its supposed to be this way. as soon as she sees me we have to get alone somewhere. we never talk on the phone and through our IMs she just always makes an excuse to leave. i got her a christmas present and a birthday present and she didn't get me anything (not that it matters, its just the idea of it) even when i'm not in the mood she'll just start kissing me until i give in. if i don't give in that she gets really quite and wants to go home. she'll complain of a headache or something. she claims she loves me but it doesn't feel this way. shes the first girl i've ever been with so everything new to me but it would be nice if she asked me out atleast once