Macbook Pro Yosemite Update Progress

Hey y'all!

I have a MacBook Pro 13" that is a few years old (apx 4 - 5 years old). I have been putting off updating to Yosemite for quite some time but just this weekend on Saturday I decided to go ahead and update. Well, its been 3, going on 4 days and the progress bar has not moved from the midpoint. I have a white screen with the Apple logo and the progress bar right underneath. What should I do? Is this normal being that I waited so long and have to download a ton of more patches and such? All the help and/or pointers would be appreciated!

Thanks y'all,

NIN9205