Spotting 4 days before AF? Implantation?

So on Wednesday 4/4 I had some lower back pains and a small episode of cramping. Not even comparable to AF cramps (much lighter) and that night I had noticed light pink spotting only when wiping It was a really small amount and it only happened like twice followed by nothing. Following day 4/5 I had some brown spotting only when wiping and also same thing today 4/6. My AF is due on 4/8 and I’m wondering if this was possibly implantation bleeding? I’ve never spotted that early before AF, and I took a hpt (not FMU) a few mins ago and it was a BFN? What do you guys think?! Anything helps!