Wanting a third so quickly?!

I'm so confused. My whole pregnancy with my 2nd baby I kept saying I wasn't having anymore. Well now that I have two beautiful little boys, I want another. I just love the idea of a big family. Ugh. Right now I have a 4 year old and a 4 month old. I want the third to be closer in age with my 4 month old. Any other women go through this?