Like to know the difference between implantation bleeding and period..is it possible to have implantation bleeding one day before period date??today CD27 of my last period and I tested with UPT which shows a very faint 2nd line but after 7 to 8 hours I started bleeding(very little amount)..I don't know what to do and what to expect..I was on susten sr 300 from CD 16 to 25 followed by letroz 2.5mg from cycle day 3 to 7..