12/12 lighting question??

My plant has been growing for about amonth and a week and it just started it's preflowers the other day... Can I just leave the lights off for a day or two so that the lighting schedule will reset itself and i can start 12/12? Or do i need to do it like 18/6 and so on till I get to 12/12

just keep it 18/6 until you want to do 12/12 and whenever you want your lights off switch them off for 12 hours signifying to the plant time to flower....

Preflowers? That means it is already in flower.