I also have lining issues, two years ago when I had a successful natural FET trf I did the following -
Drank pineapple juice (not from concentrate), ate brazil nuts, selenium tablets, acupuncture, co enzyme q10 tablets, wellwoman and drank milk. I cant say for sure if these things helped but I had previously had two months whereby the trf could not go ahead due to poor lining and fluid present. The best my lining has ever been is 7mm and I initially fell pregnant with twins.Sadly only one of my babies survived but I now have a beautiful 15 month old daughter which I am eternally grateful. I am told the lining grows approx 0.5mm per day so it may not be too late to take some of the above to help. I definately recommend acupuncture - it can help with blood flow to the relevant areas.
I was supposed to have a further FET this month and my lining on day 10 was only 5.2mm. The consultant was more concerned by the fluid I had present. They told me that somebody through my clinic is successfully pregnant with twins on a lining of 5.5mm! Many clinics have minimums of 7mm or 8mm so there is still time. How long are your natural cycles normally, you possibly still have plenty time. Are you getting blood test to check for ovulation? Sorry I cant give any words of wisdom re your follies, maybe its too early in the month to see much happening. I have pushed for another semi natural cycle with oestrogen tablets to help build up my lining - maybe worth asking about.
Sorry for waffling on - I hope the above is of some help.