Can you lose Trust Level 3 without Blizzard notifying you?

Go get 20k more before your time is over D:

Unless you spend some time tracking your stats, there is not a concrete way to know what you were truly missing. If I have to guess, after checking your stats I think the problem was here:

This is the 3rd “cycle” of thrust levels (every 50 days), during cycle 1 and 2 you viewed a lot of threads, but the low amount of viewed topics you have makes me think you missed the 3rd cycle mark.