Odds are that you have already ovulated once you're in your last active pill. However, you did miss a pill and then had unprotected sex so the possibility is there. You can wait until wednesday for your period to arrive. If you want to be on the safe side, you can also take a morning after pill up to 72 hours after having unprotected sex, which can be purchased over the counter at your local drug store.
Did you take your missed pill the following day? If so, you should be protected.