Is it possible to ovulate/get pregnant on cd6?

Julia
My cycles are usually 25-31 days long, my period lasts for 5-6 days. Last period I had was 13/05-18/05. I had sex on the 5th day (pull-out only unfortunately) and even my gynecologist says it's really unlikely to get pregnant on that day, but now is cd17 and I still haven't ovulated yet. My cervix is firm and the mucus is sticky and white, so is it possible to ovulate (and get pregnant) as early as cd6?