Do you Candle them? If so, a lot of times you will be able to get a response from them and see them move with a light squeeze here or there
Of course I may just like to play with my eggs too much
As for cutting @ day 60 it should not be a big issue if you have been incubating at 89. 60 days is not something to get to worried about. If you are scared to cut I would try the candling response to see if they are alive and kicking.