No candling until day 6 or 7, leave in any 'maybe' eggs. Candle again at day 12 and day 18 before lockdown. No chance of exploding eggs, no messing with very small delicate heat sensitive tiny embryos. I always reccommend that, candle the all eagerly at day 4, start tossing by day 6 or 7 and get them every three days unti lockdown with a quick peek at the end of day 20 when I see the first internal pip. Bad, bad, I know, but I know I can trust my incubator to do it's stuff. It's magical, I swear. I have been much better this time, am currently day 14 and have candled twice (day 5 and day 9). Will candle again tonight and once at lockdown.
Good luck!