Nexplanon - Bleeding after a year and a half

When I first got Nexplanon in ~Dec 2017, I would have the light but constant brown discharge for like 6 months, and then everything stopped for about a year.

I began bleeding again. This is accompanied with what started as a dull and occasionally sharp pain in my lower right ovary area. Thought it may be appendicitis and was admitted to the ER at the time, they took an ultrasound and found some trace free fluid in my pelvis and cervix that "may represent mucus". The dull ache has since subsided (also concerning if it was appendicitis) since the constant pain I used to be in and today I was hit with a saturated panty liner of old blood. My WBC was normal. Right ovary .5cm enlarged

I know that fluid in the pelvis is not normal but Im unable to see if im actually bleeding abnormally due to an underlying serious condition because of Nexplanon. Worried and not sure what to do next.