Dont know if my period started?

Emily
About 4-5 weeks ago, I got the birth control implant Nexplanon. A few days after that, I've had non stop bleeding. Every day, and still today. Although today I was suppose to start my period. How am I suppose to know when my actual period starts if I'm having non stop bleeding? Please helppppp. And anyone also have the implant, I've heard negatively towards it.