Hello, and I hope I can help you today. Even if you had some spotting when you are not supposed to have your period, the birth control pill is effective in preventing pregnancy as long as you are taking it daily. Breakthrough bleeding, which is bleeding while you are taking the active pills, can happen once in a while as a common side effect of any birth control pills. In your case, because you took one late pill during this pack, that may have been the cause of the breakthrough bleeding you experience. In addition, having slight bleeding after sex can also because by chafing in the vagina or on the cervix and also has no connection to effectiveness of the birth control pill. Furthermore, because your boyfriend does not ejaculate inside you, your chance of pregnancy is still quite low from that alone. Therefore, I do not think you need to be concerned about pregnancy in this situation. I hope I was able to adequately answer your question today, and that this information was reassuring. Best wishes, Dr. Brown