How long well a hen lay fertile eggs after tom mates her

[JonathanL23]

I got a egg Saturday I cracked it and checked there didn't seem to be Whits spot on the yolk. But today I got another and it has a spot and I posted pics and others said it was fertile so how long will she lay eggs like this. I heard up to 2 weeks other source says 2 months. Also will all eggs be fertile for the next 10 days or so or can she lay non fertile too