Most growers have tried this shit at least once or twice in a controlled setting, it doesn't make a difference and if you grow from seed, dont say it does. You can shock them into pre-flowers by going from 24 to 12/12 but, the same thing happens going from 24 to 18(veg).
It doesn't matter if your lights stayed on for 24 hrs after a 24 hour dark period, just as long as you arent in full on flowering and even then it won't matter unless you did it more than once in a week or two.
Just carry on and the only thing you'll notice is an extra day of stretch.