Will BB be okay if there's no fish in tank for 2-3 days?

Well I've encountered something new and am really unsure about. I just sold my fish and due to winter conditions, the store I'm buying fish from won't be able to ship until Monday. Will my tank be alright without fish in there for 2-3 days? I hear that the BB can last quite a long time without an ammonia source, but I'm not 100% sure. Not sure if I should put 1-2 drops of Ammonia in the tank in order to get at least SOME kind of ammonia.

Ghost feed some flakes in to provide what the BB need, no need to add ammonia.

Thanks Gryphon, I have 2x HOB filters (waiting to upgrade to canisters), so do you think I should crush them up and add them right next to the filter cartridges so they get caught in the blue sponge?

You'll be fine. Most likely your tank is still breaking things down from when the fish were in there. For instance at the shop we don't do anything special between fish being out of the tank for up to week.

Either way works.