I only know two things about popping zits:
[*]You're not supposed to do it!!!
[*]If you're going to do it, use two Q-Tips to pop it instead of your fingers so as to make sure the oils from your hands don't get into it and make it worse off...
In my experience, every zit I've ever popped has either left a small, small mark... Or, I continue to have them grow in the same spot from time to time. I recommend leaving it alone and letting it take its course, or using either Neutrogena On-The-Spot Acne Treatment or MK Blemish Toner on it. Or, something I've always read about celebrities doing, is use tooth paste (the actual paste, not gel), and they apparently reduce a good amount over night or within a day.