Implantation or period VERY confusing!!!

Hey guys.

So my last monthly period was February 28th. We just started ttc again I had an ectopic in December. Have had normal 28/29 day cycles since.

I started spotting on Friday (so 5 days ago) very very light. Dark in color. Not a lot. On and off. Rarely there’s some tissue. I saw one extremely small clot once.

Is this an early, extremely unusually light period, or implantation bleeding? My period is not due for 3-5 days and all pregnancy tests pointed to no, I’ve never had bleeding like this.

Help!!!