Nexplanon, period cramps no period

I’m on nexplanon, I have had cramps for a week straight and feel like I am going to get my period, but it hasn’t came yet. I know nexplanon can make you not have a period at all which has been happening to me, but the period cramps with no blood is new. I also have been having headaches, and have been so tired, but these sharp cramps are worse than any cramp I’ve ever had. All I want to do is lay in bed with a heating pad. Has anyone else experienced something like this