Is my Nexplanon still effective??

I’m not sure if this is the appropriate subreddit for this, but it’s worth a try…

I’ve had my Nexplanon inserted back in May and have had no significant problems with it. However, around the end of June/beginning of July, I started noticing a serious increase in my appetite. It felt so bad that I consistently ate and could NOT ignore my hunger.

About two weeks ago, I was prescribed Phentermine as an appetite supresor, and it works wonders.

Out of nowhere last week, I started getting awful cramps and started my period. Note that I hadn’t had my period since before my Nexplanon insertion, and I do wonder if my Nexplanon is too deep into my arm to where it isn’t effective (I’m not completely sure how it works).

Is there a reason why this is happening? Is there a correlation between these two? Is my birth control even still effective???

I have not been sexual active as of this month and prior to the Phentermine.