We all have different goals and expectations. If you are breeding for show, breeders often wait until the chickens are a couple of years old to see if they are worth breeding for show. If they are breeding for improved egg-laying they may wait through one egg-laying cycle so they can better evaluate them for egg-laying. For some people with their goals it is better to wait to hatch.
However, not every one has the same exact goals. For many there is no reason to wait a year or more to hatch eggs. I don't know what your goals are or why you are hatching. Since my goals are probably different from yours I don't feel qualified to tell you what you have to do.
Egg laying is a pretty complicated business. Sometimes when a pullet first starts to lay she doesn't get everything correct. Or maybe the rooster doesn't notice that she has started laying and doesn't fertilize her eggs. It is possible that something could be wrong where they don't hatch. Most pullets sort this type of thing out in a few days. To me, it's amazing how many get it correct the first time.
Another possible issue is that when a pullet first starts to lay the eggs can be pretty small. This especially happens when the pullets start laying at a very young age. There is not enough nutrition in there for the chicks to grow very big, let alone enough room for them to fit if they grow big. The chicks have to fit the room available so they can be pretty small. The eggs do increase in size the longer they lay.
I hatch pullet eggs. Sometimes I get pretty good hatch rates, sometimes I don't. One time I had 5 eggs from one pullet in the incubator. I had 6 eggs from another pullet. There were eggs from older hens also. I could tell which pullet laid which egg by color. Of the 5 eggs, none hatched. A zero hatch rate. An absolutely horrible hatch rate. I don't think the rooster had fertilized them but it could have been something else. Of the 6 eggs from the other pullet, 5 hatched. Not perfect but an acceptable hatch rate.
Usually any chicks that hatch live and grow up well. But occasionally I lose a chick. When I do it is a little more likely to be a chick hatched from a pullet egg. The difference in mortality for the ones from pullet eggs isn't that different from the ones hatched from larger eggs but there is a small difference.
When I can, I like to wait until the pullet has been laying at least a month before I set her eggs. These problems pretty much go away in that month. The pullet has sorted out her egg laying issues and the eggs have increased a little in size. You said yours have been laying for two months. You do not get guarantees with living animals, including hatching, but if you have problems with this hatch I doubt it is because of how long those pullets have been laying.
Let us know how it goes.