Pre oestrogen for IVF

nm712

Hi everyone, I hope you’re all well. I’m due to start my second IVF cycle and was told to take estradiol 2mg tablets twice a day up until day 3 of my cycle.
I had a scan today as I started my period but then it’s just stopped after having a day of normal bleeding. I was told by the doctor today that my Endometrial lining is over 16mm and that they don’t want me to start stimulating until next cycle. I’m really confused as I thought that was the point of the oestrogen - to thicken my lining? Would really appreciate everyone’s advice as I was already anxious and now I’m just a big mess as I was so geared to start! Thank you in advance.
P.S: my first cycle was unsuccessful as we only got one embryo!