Since you are not positive about the date, I would wait another day or two. Then if nothing has happened, you don't have much to lose by opening the bator and taking out some eggs to candle. If you can't see movement, you could try a float test. If you think none of them made it and you are not squeamish about it, you could open them and see how far they developed, or if some weren't fertile, etc.Sorry it isn't going as planned. I hope you wake up to hatching tomorrow!