my periods are usually around the same time, sometimes a few days early or late. but the last couple months it has been 7-10 days later. i had unprotected sex on 8/1/08, 8/4/08 and 8/6/08 then i noticed clear thick and sticky discharge around the 4th or 5th so i assumed i was ovulating. my last period started on the 19th of july. i noticed pink spotting only when i wiped on the toilet. then it turned redish brown. it has been getting gradually redder and slightly heavier, but VERY light compared to my usual periods which are heavy. i didn't experience my usual syptoms and my period isn't due until the 19th (if it is the same as last months). some women have said they learned they were pregnant after having implantation bleeding that lasted longer than a week. my spotting and light bleeding has lasted 8 days so far. if this is my period i've never had a period this strange. is this implantation bleeding or a very weird period?