I never had implantation bleeding, but my sister and I got into this conversation one day because she did have it. She waited about a week at the earliest but usually she preferred to wait until her missed period. Same with me, I preferred at wait until my missed period but its completely possible to get a BFP before that, so good luck!
I had implantation bleeding on a Saturday (I charted and was supposed to implant likely the day before) and my period was supposed to start that coming Wednesday. Because I knew when I was supposed to implant I got excited!!! So I tested the day of my MP (Wednesday) and got a BFP!
Re: How many days later ...
Mary (33) and Michael (33)
Diagnosed with PCOS in 2002, Married 4/10/10 TTC #1 June 2011; LAP and tubes flushed in Dec
2012: 6 Clomid Cycles, all BFN; RE consult Nov 2012: SIS (all clear)
2013: 3 Femara Cycles with IUI, all BFN August 2013: Follistim/Ovidrel = 3 Follies, IUI on 8/29.
BFP!!!!! 1st Beta = 204 on 9/12/13 2nd Beta = 774 on 9/15/13!!
First U/S 10/1/13 - It's TWINS!!!!