Light brown discharge with hints of pink 5dpo to 8po and still on

I had an IUI and 5 days later got my first sight of some lightly colored discharge... So I was happy and thought it was implantation bleeding. On 7dpo I saw a small darker spec in the discharge like dried blood but very tiny. Nothing on 7dpo but 8 dpo light brown colored discharge is back. I have always read that implantation bleeding is only 2 days ... But I'm 6 days away from my period. Has anyone had implantation bleeding for more than 3 days and got bfp?