Please let me know if you speculate this as a period or implantation bleeding: For the past 4 months, my period has had a 35 day cycle, before that; it was 28-31 day cycle. My concern now is that my period has come in on the 31st day. I had no PMS , in which I always get. No cramping at all. This so called period was for 3 days only, my range is 4-7 days, usually 7 days. It came out pink, not red or brown. However, there was clotting the night before it stopped. My flow is always usually heavy than light. This period was pretty light, not like my usual period. Please let me know what you think. Thank you.