When you get checked the Dr. or MW uses sterile gloves because you can introduce bacteria and therefore cause infection so I wouldn't do it yourself. Plus it's a skill that takes time to learn so you probably won't be very acurate, I plan to leave it to the professionals!
1 finger = 1 cm dilated... 2 fingers = 2 cm dilated and so on???...so whats fully dilated... *gulp*