Take the pill you missed immediately so you are all caught up.

It is unknown whether you could have ovulated or not. Most pill packets say that missing one pill will not compromise your protection, but only if you remember to take it the next day...

Of course there is a chance you could have ovulated and possibly conceived, but remember, the pill works in many different ways to prevent pregnancy. Even if an egg was fertilized, the pill thickens the cervical mucus while thinning the lining of the uterus so it is a lot harder for an egg to implant in the uterus.

If it's not too late, you might want to consider emergency contraception, just in case. EC is most effective when taken within 72 hours of unprotected sex, but it can actually be taken and still remain effective up to 5 days after intercourse.