don't worry yourself too much buddy. I did my medical in July 2017 when renewing my work permit and it was still valid when they received my application . on my GCMS note it was extended till June 2019. also, they always say security not started , and suddenly you will get DM out of the blue .Dec 11th 2017 still waiting 1 dependant. Upfront medical was done and now expired. Security check not started..
my AR is December 14 by the way .