How long is ovulation?!

Kandy • 43 year old TTC... Keeping the Faith!
Hey ladies so I need a little help...so I took OcPK this week! 
Monday and Tuesday I got a "flashy smiley" face (morning and evening).....Wednesday AM "flashy face", Wednesday PM "Solid Face"......Thursday AM "solid face"....I cannot test anymore because both test holder has the "solid face" and it won't let me test! So my question is how do I know when I ovulated? And do I continue to BD? PLEASE HELP!!!!!!