Thin endometrium

Hi girls :)

My endometrium for the past months has always been around 6 (sometimes 6.9 - 6.7 - 6.3 - 5). Last cycle on the ovulation day it was 6 and the next day 4.92 (it has never been so thin). I went today to my doctor and he said this could be something sporadic of only this cycle. He did an ultrasound and the endometrium today (14 days after ovulation) was 7.8. He said everything seems normal, however, I couldn’t conceive this month and this could be the reason. I’ve been trying for 4 months now for my first baby (all exams seem fine).

Has any of you experienced something like this? Just need some support here🩷