Just be patient a little longer. Some of my banties go over the time I think they are due to hatch. For example, if you sat them late at night, then technically thats not day 1, so allow an extra day for that

I had one last year who was a couple of days late hatching, and I honestly thought they were not going to hatch, but she still sat there looking determined......so I gave her the benefit of the doubt. I never remove the eggs for at least three days after they were supposed to hatch. And then when I throw them away I never look if there is anything inside - if there was that would upset me. I prefer to think there was nothing!!!
Usually over the last day or two, you will see the hen clucking to herself, she can hear the chicks getting ready to hatch, and if you hold an egg to your ear, gently, you should hear cheeping, although not always, so don't worry if you can't.
Good luck, really hope there are chicks in there. I assume the bantam has sat ok, and not been off the nest too long at any time?