My periods usually last 5-7 days. In March my "period" was only 1 day. In April it was 4 days. In May it came on 1 day, stopped the next, came the third day, stopped the next day, then came again for 2 days then stopped. Is it possible that the 1 day period I had in March was possible implantation bleeding? I had a very strange "period" similar to this one 15 years ago with my first pregnancy, but I didn't know anything about implantation bleeding then>