Popping zits is dangerous and can lead to even bigger problems than just a simple pimple. After a zit has been popped it's now a big open wound and a magnet for infection. The sebum and bacteria mixture that comes out of the zit is going to spread around your face and end up in other pores on your face and create more acne. Also, when you push on your face to pop a zit you're damaging the tissue that's beneath the surface and making your face much more susceptible to acne scars.
Either just leave them there and treat them from the inside out with a healthy diet and lot of water, or pop them the right way. To pop a zit properly wash your face and hands, push sideways on the zit or use a sanitized needle, then thoroughly clean the area with hydrogen peroxide.