By missing day one of the pack then your chance of pregnancy did rise, if you had intercourse within 5-7 days of that occurrence then it is possible to become pregnant.
However by taking the extra pill on the second day, that would have increased your blood levels and that could be the reason for the late period.
I would wait another 5 days and if your period has not started then you will need to do a home pregnancy test.
There are other reasons for missed period .These include hormone imbalance, Polycystic Ovary Syndrome, thyroid problems, stress, being underweight, or being excessively overweight, losing weight very quickly or exercising excessively.
In order to get an answer re hormone and thyroid you will need to request blood tests for these from your family doctor. The lifestyle factors can be looked at and changes made at home/work to reduce stress etc.
Does this help?
If this answered your question please click ACCEPT, use reply if there is something else you need to know regarding your question.Positive feedback or bonus is very much appreciated.