If you missed a combination birth control pill by about 12 hours, you should take the missed pill as soon as you remember, which you did this morning. Since you are in the second week of your pack, the risk of pregnancy is lower than if you had missed a pill in the first week.
Here are some general guidelines for missed pills:
1. If you miss one pill: Take it as soon as you remember, even if it means taking two pills in one day. You should continue taking the rest of your pills as scheduled. You are still protected against pregnancy.
2. If you miss two or more pills: The guidelines can vary, but generally, you should take the most recent missed pill as soon as you remember and discard any earlier missed pills. You may need to use backup contraception (like condoms) for the next 7 days.
Since you missed your pill by 12 hours and took it as soon as you remembered, you should be fine and do not need to take Plan B.