Do it now, honestly dont think about anything and do it .. because in 2 years, 2 months or even in 2 hours it wont even matter.
But I have about fifty books at home I haven't read, there's no reason for me to buy these.
Okay, but consider this: more books.
Are you sure you're not just saying you want one because all your friends have one? Remember, it's not going to be small and cute forever, it will grow up eventually! It's a living being that will depend entirely on you for the rest of its life. Are you really sure you're ready for this?
Oh, you'll want one sooner or later. Everybody does, after all. Besides, babies are soooo cute, aren't they? You'd better hurry up before you get too old!