It is not a case that at a certain age eggs are no longer hatchable. Hatchability gradually drops the longer they are stored. After certain time maybe one or two have lost hatchability. Another day or two a few more may no longer hatch but you may still get a few to hatch. Some of those eggs can last a long time, some cannot.
The conditions they are stored has an effect too. That includes temperature, humidity, and turning. You do not want to have them where the temperatures vary, warming and cooling cycles can be hard on them. A breeze blowing on them can dry them out.
The general recommendation is two weeks when they are stored in or near ideal conditions with no loss in hatchability. Ideal conditions are around 55 Fahrenheit, in high humidity, with turning, and stable storage conditions. Most of us don't have those conditions so just do the best we can.
I store mine at room temperature and turn them daily. I set them as soon as I have enough. That's never more than a week. I number my eggs as I collect them. I use a black sharpie to write a "1" on the first egg on one side and a red sharpie to put a "1" on the other side so I know they are turned correctly. This way I can keep track of which eggs are the oldest. I do not get a difference in hatchability between the oldest and newest when it is only a week.
You are getting about 3 a day. As long as that continues I'd store them until I had 22 eggs and start them then. Will your oldest eggs lose some hatchability? Probably not unless your storage conditions are pretty harsh. But i guarantee you they will not hatch at all of you don't incubate them.
@Smileybans what kind of hatch rate did you get with those 4 week old eggs. I tried that one time with about two dozen 3 to 4 week old eggs but they had not been turned. None of those even started developing but the ones I collected the week before incubation started had a good hatch rate.