Implantation, Period, Plan B? TMI PICTURES

TMI: I will be including pictures of discharge.
For context, my period was supposed to be due on March 25, and I have a regular 27-28 cycle.
In the heat of the moment, my boyfriend and I had unprotected sex on March 15 (10 days before my expected AF), and he pulled out and came a little bit away from my vagina and I "cleaned" him right after. Then about 20-ish minutes later, we started having sex again, and I'm a little worried that some pre-cum might have gotten into me. Anyways, this was about 2-3 days after the end of my predicted fertile window.
About 60 hours later (March 18), I took plan b. Two days after taking plan b, I experienced bloating, sore breasts, small twinges, and fatigue which continued for the whole week. 
However, 5 days after taking the plan b, I noticed some spotting/light period? This was 2 days before expected AF.
It was pink-red, and I'm not sure if I saw a pretty big clot in the toilet and but I did see really tiny ones on the tissue. I continued to see pink discharge the next day when I wiped but less. On the 3rd day, it turned to a light brown then into a really dark brown-red the 4th day.
Would this just be an early period due to plan b or would this have been implantation bleeding and could I be pregnant?
Picture not mine, but this is basically what my discharge looked like for the first two days of spotting when wiping.
And this is what my discharge looked like the last day.