Whats a cervix?
How far do you put it in? You need to go see a gyno fast and stop doing that. seriously
I have no idea how far it goes because I'm not quite sure how long my vagina is. However, I have inserted a tampon to the point that no applicator sticks out of my body.
I doubt very much that you've managed to penetrate your cervix because you would be in such pain. The cervix doesn't even let sperm through except for one 24-hour period when you're fertile. There is a small area behind your cervix that you may actually be reaching, but you should talk to a doctor.
If its behind the cervix don't you have to go through it?