Could Spotting In The Mid Of The Cycle Be Due To Implantation?

My period is normally irregular. 24-28 length cycle. LMP on April 9th. Started spotting on the 30th for three days, but only saw blood when wiping. This is the 4th day and the blood is more but not the amount of a normal period. Very small amount in pad. Normally I flow heavy from the start with my period. Could this be implantation bleeding?