Starting IUI

Hi ladies, I was just wondering what your thoughts and experiences are. So we've been ttc for no 2 for 18 months in total. We fell pregnant at month 7 and miscarried at 9 wks. I had retained tissue so we took a couple of months out. We've been ttc for 4 months since. I have low Amh at 8.4. As I'm based in the UK the readings are slightly different, so I'm not sure of the equivalent in the states. Yesterday I saw an NHS fertility Dr who said that my age was making him twitchy. I'm 35. He advised we keep trying and if nothings happened by Christmas we should start IUI in Jan. Do you think we should or should we carry on naturally? Has anyone been in a similar situation?