Geritol + 20 pk OPK

When do i start? AF started the 27th and has already started to taper off. Im on my "Hudini" day. Meaning you wake up with no blood so you think its over and then at the most inconvenient time of the day when you are least prepared AF just shows up again 🤣😖. But i have around a 28 day cycle and a 5-7 day flow but also im VERY irregular lol, so my question is when should i start the Geritol, and the OPKS? and what time of day xo i test?