I supposed to start my period today I did but all of a sudden it stopped it's back on now not heavy not light I loked up it said implantation Bleeding?

Possibly. Time will tell if it is implantation bleeding. May also try doing a pregnancy test and repeat in 1 week if negative. It can also just be a change in your menstrual pattern. Many factors can effect your period such as pregnany, medications, medical conditions, stress.... See a doctor if any further concerns.