incubating eggs

I know that incubation is roughly between 18-21 days but I've got 1 egg in my brand new brinsea advance bator that's doing really well. Should I go into lockdown on the 18th day or wait until near the time when the egg shows first signs of internal\external pipping? Tomorrow will be the 12th...

Several recent postings made be think that the info below (still in progress) might be useful, especiall y in regards to fertility and infertility problems. Note: if the problem is serious or you can not determine the cause it is best to go to an experienced avian vet, to check the breeding...