Hiya Lisa, sorry it's taken me a while to reply, been at work myself.
Danios are egg layers. Apparently they only take a day to hatch from the eggs being dispatched, now that's a quick delivery! lol
It may be worth checking t'internet to see if your fish are suffering from swim bladder, if you Google the symptoms your aquatic friends have it may lead to this illness, which is easily treatable (by feeding them a couple of peas, cooked, and not feeding them after for few days)
Hope they ok.
Also sorry to hear you didn't get the dog too, some folks are gits eh?