Ive always had a sharp stabbing pain/cramping that hurts A LOT but luckily it only lasts for a few minutes!
As far as the cm I would keep an eye on it for a few cycles just to get an idea what is normal for you. According to web sites on the subject you might have to (here comes the tmi

) insert a finger and check that way. As you may know its supposed to be clear and stretchy if you put it between thumb and forefinger- hence the world 'eggwhite'

If you dont seem to be getting anything that way, after a few cycles, maybe 'pre-seed' would work, as it helps create a beneficial (cm type) environment for spemies when your ovulating! (I havent used it myself but it really seems to work for some couples).
Also, OPK's or even a Clearblue Fertility Monitor can help you pinpoint ov.. I really like the monitor myself, but its all down to what you find works for you!
Hope this helps, xxx