Latest batch of 10K egg hatches.
Took me over a month to collect nine 10k eggs, but hatched them tonight:
Porygon x 3
Dratini x 2
Mareep x 2
Aerodactyl x 1
Lapras x1
But more importantly, I got over 20k stardust which went straight to my 2nd Tyranitar, now at level 29 and begging for more dust...
Answers
I am on a similar situation, for me it seems like the drop in 10km eggs is more closer to zero than ever. Since the Go fest and the 1 year anniversay event I have got exactly 2 of them only. One at 07/08, and the other on 27/08, exactly 20 days from one to the next one...I always save them to make a 9x openning but at this rate it will take me months before I can get to that number.
I am level 39, playing since day 1 and never has took me that much time to get a 10k.
I usually hatch one 5k or a 2k plus a 5k daily using my infinity incubator only (all my coins were going for raid passes until I cut back on raiding last week). I know it's RNG, but I swear the 10k drop rate increases as I gather more 10k eggs (like getting more revive when that's all you have in your bag). When I finally collected 6 of the 10k eggs, I bought 2 incubators to polish off the last 3 of my 5k eggs, then collected the last 3 10k eggs in 4 days.