Trying for a girl - shettles method. Anyone try this ?

So my husband and I are trying for a girl - I have read the shettles method and I am supposedly supposed to ovulate tomorrow. I have been taking ovulation test and it has been blinking for 2 days( which means high chance but not ovulating yet) The last time we had sex was Sunday. So I guess I am nervous if I don’t ovulate tomorrow and don’t have sex today if I will lower my chances. If I do ovulate tomorrow and if the sperm actually does live in you for 5 days I guess I should be good for a chance ? I am reading to try for a girl you are not supposed to have sex on ovulation day and to do it 3-4 days before. I am hoping I ovulate tomorrow and not on thursday or Friday. I am also upping my calcium and magnesium. Has anyone tried the shettles method ? Btw we really want a healthy baby in the end ! We have 2 boys and one has a missing chromosome which severely affects his central nervous system - so please no negative comments about how trying for a gender is ridiculous and i should just be hoping for a healthy pregnancy- trust me i do as i already know the depression and emotions from my disabled baby (who i love more then ever) Its supposed to be for fun ! Thanks all!