thoughts on Shettles Method

I got a positive OPK today based on the Shettles method for conceiving a girl would this be when I should stop having sex or is today ok since technically ovulation won't actually happen until some time tomorrow or day after.? 
YES I will be truly blessed for either or just a health baby . Just trying for fun . Have three boys already and this will be my husband and I LAST child lol . 😩 would love to have my girl . Anyone true this Method and it worked .? And what did you do .?