First off, I'd say you hit your ov time perfectly!
Actually, there is no set amount of time after ov that the os closes. It varies, sometimes greatly, from person to person. I am open for up to two days after ovulation. My CM is gone, the thermal shift is obvious and my pre-ov bloat and cramping ramp up as disappeared yet my os is still open...but slowly closing. (My midwife says mine is the longest closing process she's ever heard of.) However, she has worked with women who's os is open for only 24hrs. Their os slams shut seemingly hours after the egg pops. Others, like me, take a little longer. This is why it is so important to look at several ovulation signs to pinpoint when your egg is bursting out.
Queer poly family trying since October 2006. Currently using a known donor and no medical interventions.