Gan and Jude,
For medicated FET, you DONT OVULATE. the medication prevents u from ovulating and build up your lining to minimum 8mm. So you dont worry about ovulation, only need to worry about lining.
For natural FET, you HAVE TO OVULATE in order to proceed the transfer. You lining needs to meet at least 8mm as well. So you have to worry for both ovulation and lining.
if you are doing natural, u have 1 more chance to conceive naturally bcos u can have sex during ovulation.
but for medicated, you rely only on the embbies transferred.