Implant...period?

Hi,

I got the arm implant on June 12th. On my bc pills i stopped taking them this weekend which means i should have my period sometime this week. but it has not started yet. and I was wondering if that would be normal with the implant? To clarify if the implant would change my cycle even tho i finished my pills. I need some advice before i start freaking out and thinking im late...i had sex with my boyfriend on saturday of last week. completely protected and toom a plan b just incase. But i need some advice on weather i should worry or not. Thanks ladies!