Well I'm on day 7 since the IUI and I haven't had any discoloration. I'm just trying to be patient.
No, implantation occurs 6-10 days after the egg fertilizes, definitely not after 2 days...since the embryo would only be 4-cells and not have the capability to implant.
I imagine it's entirely possible (that it could be implantation), although I think it's supposed to take longer than that. They say 6-12 days to implant, but I already busted that myth. In March mine only took four days after ovulation. (ended up being a chemical pregnancy unfortunately) So who's to say it couldn't happen in two days? Maybe the fertilized egg was able to travel a little more quickly than usual. Good luck! Crossing my fingers for you! :)