For the pregnancy monitor to indicate that you may have signs of implantation (spotting, triphasic pattern) these signs must occur during the expected timeframe for implantation. While it can happen a few days earlier or later, implantation of a fertilized egg typically happens between seven and ten days past ovulation. When signs occur outside of this timeframe, the pregnancy monitor takes a conservative approach and does not flag them as possible implantation signs. Also, keep in mind that it is possible to be pregnant with no signs of implantation at all, just as it is possible to not be pregnant and experience what look like implantation signs. You will only know for certain whether or not you are pregnant when you can reliably test once you are past your usual luteal phase length.