I'm 36 weeks pregnant 3cm dialted 0% effaced what does the 0% effaced mean?

No worries: Your cervix is open but you are not effaced. The average cervix is 4 cm. The cervix needs to thin out to 100% (which is very thin) so it can open up further to allow the baby to come trough. If you are dilated but not at all effaced there is no worries you will have a baby soon! also, if you start effacing and laboring we would not stop your labor at this point!

Not thinning: You are due to deliver in about 4 weeks. This is probably not your first delivery if you cervix is open 3cm, but that's ok. Effacement is cervical thinning. Right now, your cervix is full and thick - maybe even an inch thick. That is going to get as this as a piece of paper and almost 6 inches around when you deliver! pretty amazing! (and then go back). You are right on schedule with cervix status.