Just a question

Could you be pregnant after having a period? I think it was my period cuz it lasted for like 7 days n it was heavy but idk what implantation looks like. I took 2 tests and they were negative but I’m still kinda like maybe i could still be prego. I wanna take a blood test but ik i should jus wait for my period. Ik im definitely not if my period comes again right?