They look normal to me, eggs are supposed to dimple about this point. Remember they are hatching in 8 days or so,

As for cutting, wait another 5 days, day 55, then pinch an area that is dimpled and you can feel nother but the shell. Use cuticle scissors or some other small scissor and sterilize them. a dishwasher at the dry cycle is perfect for the steam. then make one single cut at the pinch about 1/4 inch. You will end up with a V shape.

As a first time I would not cut until day 58 but follow the same procedure. This way your nerves will not be too frayed.