Nexplanon & Periods

Victoria • 19. SoCal. Girlfriend. Viviana`s mommy. RAVER.
I've been on Nexplanon since October 2016, haven't had a period since November 2016. I woke up this morning to some super bad - what felt like period cramps in my lower belly and the arch of my lower back. It seriously felt like early labor pain. Is it possible to have "period cramps" without getting your period while on Nexplanon?
Thanks in advance