My macbook pro is not starting up?

Okay, I have a problem. My Macbook Pro isn't starting up. Like it is, but it's taking forever.

You see, Safari was lagging and I couldn't force quit it, so I just held the power button and after as bit it shut down. So, then as I'm turning it on it takes a good 8 minutes to get past the white apple screen with the loading gray icon and then, 15 minutes to get past the light blue screen. Anyways, after that's done I proceed to my desktop, where I can see everything but I can't click on anything, I can move my mouse but it has the colorful loading spin wheel.

After 10 minutes I conclude it's not going anywhere, so I repeat the shut down process only to make it worse. Now it's not 8 minutes but 12, and the blue screen took 25 minutes before my laptop's battery died. Right now I'm trying to do the Safe Boot and a loading bar has come up and it's moving extremely slowly.

Should I be worried? I am already, but is this bad enough so that I have to take it to the Apple store? I've got some pretty important stuff on that computer and I really don't want to lose them. Please help?

I want to do everything possible before I take it to the genius bar, help me pleease!!

Oh, and hi to everyone on the forums.

It's possible your hard drive is dying or may have already died. Do you have a backup?