Birth control

So I am 19 years old and I was finally able to get the birth control implant in my arm back in September of 2019. I had my period for about 3 months and then it stopped all together. Is this normal? I know that the birth control can make your period stop altogether but I only heard that happens when you are a smaller sized girl. I’m 5’9” 230lbs and I never heard of this happening to someone like me. I did take a pregnancy test two months ago just to check I wasn’t pregnant and it says I wasn’t. Should I be worried?