Did I miss my Ovulation period?

My husband works out of town & only comes home once a month. Since we are TTC we made sure he came home during my predicted ovulation according to an online calendar I know it's not always right but I didn't have anything else to go by. Anyways my predicted ovulation day was Saturday Aug 22nd. I took an OPK Wednesday @ 5am that was negative then another Thursday @ 12pm that was positive. My husband came home Thursday night & we BD. I took another OPK at 5am Friday morning that was negative. & Sat & Sun were negative as well. We BD Thurs, Fri, & Sat night. But I guess what I'm wondering is could I have started ovulating some time later in the day Wednesday & stopped ovulating before we BD Thursday night??? My husband came home Thursday night & left today(Sunday). Luckily in 3 weeks me & our daughter will be moving with my husband so we will have plenty of chances to BD lol. So I won't have to worry so much about it.