I recently went to my obgyn I'm 36 weeks and she said my cervix is a -1, what does that mean?
-1 is normally an indication of what OB/GYN's and midwives call station and it indicates where your baby is in relation to the opening of your cervix/crowning. It's vertical benchmark - meaning how high baby's head is in your pelvis.
-4 is when the baby is still high up in the pelvis. As baby moves down, the numbers increase - so baby goes from -4 to -3, from -3 to -2, and so forth. Keep in mind the numbers start in the negative (-4) and count up to the positive (+4).
Your baby will move through the cervix at around 0 station, so right now your baby is well-engaged in the pelvis - a perfect position to start preparing for labor.
When your baby reaches the +4 station it means he or she is crowning and about to be born.
These numbers are numbers doctors and midwives use for reference more than anything practical. It's normal for a baby to move back and forth a little, especially once they reach the positive stations. This is a good thing and gives your body time to stretch for your babe.
Babies can also move rapidly, completely ignoring doctor-assigned stations and flying out quickly :)