Hello, and I hope I can help you today. Modern low-dose birth control pills are extremely effective, and it is not recommended that if you miss a pill and take the one you forgot the next day you are not significantly an increased risk for pregnancy that if you would taken the pill properly. Furthermore, deviating from your schedule for taking the pill at a different time than what is expected frequently can cause breakthrough bleeding (which is a small amount of spotting outside the time when your period should come). This is due to the drop in hormone levels that occurred in the one day that you did not have a pill in your system. So in summary, your side effect of spotting are not caused by implantation but rather as a small withdrawal bleed from the hormones during the 24 hours where you d forgotten your pill. The bleeding will likely stop within a few days, but even if it does not your pill is still effective in preventing pregnancy. The bleeding will resolve itself by the time you re on your pill-free week and certainly when you start your next pack your regular cycle should resume when you take the pill daily as close to the same time as possible. I hope that I was able to adequately answer your question today, and that this information was reassuring. Best wishes, Dr. Brown