I didn't submit PCC at the beginning, later when they requested we uploaded through webform and sent with courier as well. I actually have lived in 4 countries longer than 6 months so I'm working on getting PCC from those countries also, even though they were not requested but I guess they will need them later.
Our lawyer says that GCkey often doesn't reflect reality so it's better to rely on ECAS, it is updated slower but with relevant and actual information. In ECAS they don't reflect if they received your documents, but most likely they received as it takes 2-3 weeks for them to get what you send.
I really wouldn't worry in your case, it's still too less time since they received your file and also consider that now it's holidays time, so they are probably going to be slower. I think you might hear something in January, as it is known the beginning of the year to be very productive for them.
And thanks a lot for valuable advice on calling to verify my application status oven phone. Definitely going to do it.
Wish you all the best with your application