Nikon DSLR is acting a bit slow?

It jusst started up a few days ago but, I have a Nikon d60 (i've had it for a few years) and now when I take a picture (even with a fast shutter speed) it takes a moment for it to reveal the photo (slow playback I guess).It has done this awhile ago and I pushed one button and it went back to normal but I don't know what to do now.
Or even how to explain what is going on. Help if you can, thanks in advaced!

Added (1). I just formatted it and that's when it started being weird:/.

I'll try it again though, but the card is empty right now.

Added (2). I don't check it after each shot, it just bugs me and I want to know why it's doing that.
Yes I go into the cameras menu and selet format memory card.
It's still slow.

I would think that buy now you would be confident enough using your camera that you wold NOT have to check each shot using the cameras LCD.

If you just shoot with confidence and only check those images shot in unusual lighting conditions, you will save your battery power for shooting photos rather than continually looking at your LCD.

Did you format the card using the format feature on your camera? Your camera will format the card using the correct FAT scheme and will write the correct file folders to the card.

It is now time to throw away the memory card and replace it with a new one.

http://keerok-photography.blogspot.com/2011/05/how-to-keep-your-memory-card-healthy.html

Sounds like you've never formatted your memory card. If you just erase photos after downloading them to your computer, the photos actually leave scattered bits of electronic data throughout the card. Though the camera will tell you that there are "no images" on the memory card, it's not completely empty and will slow down over time.

Just format your card in your D60 camera, not in the computer, and you should be fine.

Edit: Let me add one other possibility. Did you change the way your files were saved from JPG to either RAW or JPG+RAW? The other two methods of saving files (especially the second one) will take more time to save. The other possibility is that your memory card is wearing out (just like we do!). Might be time for a relatively inexpensive replacement. Be sure the new SD card has a high enough speed rating. That may be your best solution. BTW, as inexpensive as memory cards are, it's pretty reasonable to have several.

If the noise reduction is on it will take time to process the image.