Tmi no pics. Question!!!

So af is supposed to be here on the fourth. We did the baby dance all through my fertile window. I've been feeling odd and my boobs hurt a bit. They're bigger. I had a bit of spotting today which was a brownish color only there when I wiped the first time this morning. Could it be implantation bleeding? I know we aren't supposed to test until first day of missed period but I'm anxious. Haha I took a test two days ago and it didn't work. Nothing in the control window. I want to take another and know I should probably wait. :/ can implantation bleeding be that light that I only see it once or twice on tissue?