I have been checking my cervix for a few years now, so I'll try and help you.
Usually, after I have ovulated, my cervix goes very low, (you don't have to 'dig' around to find it!) hard, and open. Personally, my cervix never really 'closes' completley.
If you have had a vaginal birth or late miscarriage, your cervix may never close properley.
Are you checking your CM alongside this? I have found that although its helpful to be able to lacte and 'know' my cervix, it dosent give me much of an indication of where my bodys at - apart from being very high and soft at ovulation!
I've never tried to locate my cervix, but when I had IUI the nurse told me that my cervix would open a little just after ovulation. Of course this makes sense, to allow the sperm to get through easily at the right time. So, I would imagine the cervix stays open a little until the egg would no longer be capable of fertilisation - which I think is about 24-48 hours after ovulation.
I imagine you just need to get to 'know' your cervix though to discover what is usual for you personally.
I can "ditto" Maries post....your cervix should be high & soft at ovulation time.....it should also be slimey to the touch & your CM should be like an egg white consistancy,stretchy & clear......saying this my body used to confuse me so i started using ovulation predicter tests to be sure.