Hello,
I can totally relate to your feelings! Myself, I have two lovely sons and for the time being I do not want to have more babies in case it would be another son. Also for us the IVF/MS route is somewhat closed for us, as I think the cost is immense - and also there are no guarantees for a pregnancy to occur. Now to your questions - I do think you can sway the odds, but of course there are no guarantees there either...If you decide to try again, prepare yourself that it could be another son on the way.
However this is what I would do if I ever change my mind and want to sway for a baby girl:
1. Have a blood test taken (on whole blood not serum) and check your calcium/potassium/sodium status. In case your adrenal glands are overworked you do not absorb any girlsupplements so you need to cover your basic need first (with other supplements and a personal recommendation) and then start with girl supplements; for instance calcium, cranberry etc. Also a perfect digestion is needed to absorb any supps - take living enzymes with the supps!
Personally I believe that your body can be acidic (due to the modern junk ffod diet) but the vaginal area could be too alkaline due to disturbance of the natural flora. 2. Therefore check the PH-status which should be aound 4,5 when you do not ovulate (as it changes at that time and around). I do not believe the girl-diet - instead eat a normal, healthy diet, sugar and caffeine almost eliminated as those stimulants are not healthy anyway...
3. Finally, I recommend frequent BD (to lower the sperm count) and have a cut-off consisting of three to two days prior to ovulation - I know you have already tried timimg but did you try it together with changing of the vaginal PH-status as well as with the taking of girl supplements?
I wish you good luck with your girl-attempt, but most of all I wish that you would be happy and contempt with your four sons, they are such a blessing to you and you are still that same special person and mum in this world, even without a DD!
Best regards,
SwedishMumof2