If you feel more comfortable then candle and tap them and listen, if they have an internal pip, you can make an external breathing hole, I think its early yet, but only you know for sure how your hatch went and what you feel is going on in there. I use the tiny drill bit and make the hole close to the beak I see during candle, AVOIDING INNER MEMBRANES, I don't actually drill mind you! I score an x and then twist it in the center of it....
if you read the assist article you know how difficult it is to judge when a chick needs help, AS long as you don't touch the inner membranes your ok!