I'm just back from yet another scan only to have received more devestating news. I have read all the information I can get my hands on about thickening the uterine lining and cannot find anyone in the same situation as me, so I'm really hoping some of you out there can help in some way. Basically, to cut a long story short, my body will NOT respond to the medication to thicken the lining. The first natural cycle was cancelled in January because it only reached 4.5. Then they down regulated me again in march and started to build up the progynova. I got to 6.1 and they doubled the meds with the intention to defrost the embryos a few days later once it reached 7mm. However, a few days later the scan showed it was only 2.8!!!! We were so shocked. I hadn't bled and the nurse and doctor said they had never seen this before. They kept increasing the meds until I was on 18 mg of progynova a day, but again the lining only reached 3.7. We were really upset, but the doctor decided to cancel this cycle. I stayed down regulated using the nasal spray 4 times a day. After my next period they reduced the nasal spray (down reg) to twice a day and I started on the patches, two patches changed every 2 days. I had a scan after 9 days and we were delighted to see the lining at 5.2. The meds stayed the same and we went in for our scan today with the hope that it had reached 7mm however we received the devestating news that the lining is now 3.8 again. I'm so upset, the doctors can't understand it. They have no answers for this, she suggests I come back in on Friday but we are possibly at the stage of considering surrogacy, we have 13 frozen embryos. She said she can't up my meds as I'm on their max dose and my womb is not thickening. I don't know what to think, I've just been left so upset and with no answers. Has this happened to anyone else?