My amh was 0.5 in 2011. It was undetectable in 2013. I had it tested again a couple of days ago because I was missing my period and not pregnant and this time it came back and 0.36. Remarkably, my FSH was 6.4. What is up with that? I know that FSH can vary dramatically from month-to-month, but I thought that amh was only supposed to decline. How is it possible that mine is basically the same as it was 5 years ago and higher than it was 3 years ago?