I usually get my period a few days late but this month it came right on time and I bled normal the first day. Then the 2nd day I bled a little bit once and then stopped. The 3rd day I bled a little bit for once and then the 4th day I am spotting.

I read about implantation bleeding what is going on with me?

You are probably just having an unusual month, which is normal.
Mine changed between age 12 and 50 in a slow but steady way, with plenty of unusual months along the way.