Its been 2 days since I'm spotting (yesterday it was a little bit darker) which is unnusual since I wont get my period until around the may 22nd, and for me, the spottings happen around 2 days before I actually get my period and it is way darker. I take birth control pills but I forgot to take one of it around 2 weeks and a half ago and had sex without protection 1 or 2 days after that and he came inside. What are my chances of this being implantation bleed?