I'm not really sure if implantation last that long but I also read from one of this woman she said it is possible to have like 1-12 days of implantation bleeding. Because on my experiece I had mines twice 1st it was last week it was also pinkish/brownish and then it lasted for an hr. or 2 but only when I wipe that it is visible. But I didn't reAlly worry much because that happend to me alot of times when Im about to be on my period so I waited and waited but the strange thing this time was that it never came back 3 days past my period still wasn't there. Then another week came by which is like this tues. I had another day of wiping after I poo that's when I saw another blood this time it s a little red not red red but it was red. That's when I knew that it was implantation bleeding because after that no sign of normal period at all. And I took two tests 2 nights ago it came out possitive on both ov d tests. And then I went to the clinic and checked if it will still be possitive and yes it is thats when they told me that they'll give me a free ultrasound which is my appt. is on tues jan. 17th they said on there estimated I'm gonna be 8 weeks that day. :) if you're trying to conceive I wish you luck don't give up you'll have it soon