nexplanon / period??

Hey ladies! I've been on the nexplanon implant for 2 months now, the first 2-3 weeks I was spotting nonstop and the doctors prescribed me to take BC pills along with the nexplanon, it worked perfectly no spotting at all, today I've been experiencing cramps like I'm about to be on my period? I just went to the bathroom to pee an I wiped, I saw 3 drops of blood. What does that mean? ( currently not having sex either )