If there is no action on day 21, I would candle! I usually candle twice a day (morning and night) during lockdown, before any external pips so I can check for internal pips. Is it forced air? that's excellent news!! cuddle them as soon as they are fluffy!! I wait a minimum of 24 hours, usually more like 30. Just keep a eye on it and make sure it's peeping and membranes don't seem dry.