Hi,
Welcome to the ehealthforum and I am glad to help you out. The bleeding that you had on Saturday was likely breakthrough bleeding and not your periods.
This is very common when you miss the oral contraceptives and the risk increases when you miss three pills in a row. Now, since you are having bleeding, you can start with the fresh pack of oral contraceptives on Sunday(Sunday start) and continue using another means of contraception like condoms until you start with the pills again and even 1 week after starting with the pills. I sincerely hope that helps. Take care.