My doctor recently cancelled my FET cycle. Day 15 sono was ok, the lining was 11 mm, but the trilam was faint. So I did repeat sono on day 17. The doctor said the ling thickness was great, still @ 11 mm, the trilam was better, but still on faint side. Since we only have 2 embryos left he felt we should wait until the next cycle. He felt that based on sono result the trilam wasn t optimal to achieve pregnancy. He wanted to play it safe. My questions are, what exactly is the trilam?, and How can the ling be thick enough, but the trilam be faint?