Ok, tks grumpet, Daledale! Hope for the best!
sorry I didn't see you said yr cycle is actually 28 days. concept luteal phase defect I think is still medically debatable. But if u wanna try to lengthened it Vitex, Black cahosh supposedly can help. I was taking Vitex for a while but wasn't really tracking my O, so I can't say it has helped me. Also, some ppl say Chinese med herbs can help.
CoQ10, Ubiquinol to help with better quality egg, good diet and some exercise (not excessive) I think is prob more important ... since yrs is only 1 day short. some ppl are only 7 days in their LP. just my thoughts, but u can look up more online.
Other important Vitamin is of cos activated folate / folic acid , Vitamin D3, Fish Oil, Magnesium.