Recent illness now not laying, how long before they start again?

[Tessaf]

I have 3 isa browns, have had them for 4 weeks. They were brought at POL. For 1st 2 weeks was getting at least 1 egg a day and even had one day of 3 eggs! Then I noticed one of the girls had bloody poop under the roost in the morning. This lasted about 3 days then poop cleared up and was back to normal after about 5 days. The other two girls followed suit about a week later. They are all back to normal with their poop and they are active, eating and drinking, but it has now been 12 days without a single egg. They freerange after noon. Get fed layers pellets. Have no signs of mites or lice. Have checked vents. Does anyone know how long it usually takes before they start to lay again. Also it is spring here in Melbourne so getting plenty of light and warmer weather.