Single comb means bantam Cochin (feathered leg, no beard/muff, bantam...most likely bantam Cochin).
Which is what you want...bantam Cochins are good broodies (generally speaking).
Here's hoping you've got a girl :D
So far it's looking good. Bantam Cochins telecast early...the boys get pretty outrageously large red combs and wattles pretty early. You should have an inkling by 4 weeks, pretty certain by 8 weeks, no doubt by 12 weeks.