Nexplanon

I have been on nexplanon since January. I have spotted for a day or two within the first month but haven't had a real period. Now I really dont know. In the past few days Every time I go to the bathroom I notice a little blood. I don't know if it is a really light period or I'm just randomly spotting. Today I started getting little cramps. Does this happen to anyone else? Can someone help me understand what is going on?