Was it too late........?

The first day of my LMP was 8/8, usually AF comes around the exact same time every month, does this mean my cycle length is closer to 30 days instead of the average 28? Hubby and I BD'd this morning, is it too late to conceive? Normally I can tell when I'm ovulating because of the symptoms, but this month I wasn't sure... is there a chance I could get pregnant?