So, I took Plan B 18 hours after, what I hope was, protected sex, bc we used a condom. The day I took Plan B was on the 11th. I got my period 2 days late (the 17th) , assuming that its because of the pill I took. I know it was my period because it was red blood with clots & I had intense cramps, I was sure it was not implantation bleeding. Now, today the 28th, I noticed a little spotting, I'm worried that that's implantation bleeding. Is it that? or is it still from the effect of Plan B?