Implantation bleeding??

I have an unusally short cycle. 15 days. My period is 8 days late, nausea every morning for the last week and a half, very very very tender breasts, and very tired all the time. I had a really big pinch in my left side last night. It only lasted a few seconds but it did wake me up out of my sleep. Today, I had just a few drops/specks of reddish pink blood, but only when I wiped. Is this possibly implantation bleeding??