Nexplanon

So I got my first period since I’ve had my nexplanon but it’s really weird. I started it while I was on the toilet and it was a lot. But then it stopped and started again 3 days later. I’m cramping really bad and having weird brownish blood/ discharge coming out now. I’ve also been puking a lot the past week and a half.

Is this normal or symptoms? If not, then what is it?