Spotting.. !??

I went to the washroom at around 10:25pm tonight and when I whipped it was PINK like if I was spotting!! I'm freaking out. Isn't it too early for it to be implantation bleeding?? I'm only 5 days post IUI... I thought it was usually around day 8? It's WAY too early for it to be spotting from my period coming because that usually comes around the 14th of the month. 

Freaking Out!!!! :-(