Implantion?

Would you consider light brown spotting for 4 days 5 days before period is due to be implantion? I was suppose to get my period wed.. but started spotting on Fri. Took 3 tests and all came out negative. I don't know if it was implantion bleeding or am I suppose to consider that as my period? It was only a couple of spots, very light & only when I wiped. Been having heavy like feelings on my lower abdomen.