Depending on which weeks pills you missed, how many, and the sequence, your period could be delayed due to your missing pills. On the same note, you could be pregnant due to missing a certain weeks pills. I am not sure, but I think I remember the first week and third week pills being the most important. You can increase your chances of getting pregnant if you missed pills in these weeks. If you get another BFN, then I would assume you period is delayed due to missint pills. However, you never know.