Nexplanon side effect ??

Olivia

So I started Nexplanon on March 31st this year (2017). I usually have very heavy periods that last about 7 days. After I started my birth control, my period was about two weeks late, was very light, but lasted over 3 weeks. (in April). My next period started June 6th and still hasn't ended. (as of July 17th, 2017) I know irregular bleeding is a possible side effect but is this normal ? Should I see a doctor ?