IPhone 5- Apps showing more notifications than there really are?

So I've had my iPhone 5 since it first came out and I've had this happening since then. When I'm in the home mode (where the screen shows all of my apps), and when an app shows I have notifications, you know, with the little red bubble with the number of however many notifications it says, the number is always much higher than what there really is. For example, the Facebook app icon will show that I have 14 notifications but when I go into Facebook I really may only have 2 or 3, it seems to only do this with apps where people post comments to status's I write, like get glue too. None of my other iPhones have done this before. Not really a huge problem or anything, just kind of annoying I guess. I was just wondering if anyone else's iPhone was doing this too and if there's a way to fix it?

Only my facebook app does that. It will say I have over 10 notifications but I really only have 1 or 2. Maybe it's just a bug with the app