With implant and husband's vasectomy
, chance of pregnancy
is extremely rare and it is possibly ruled out.
Some other reasons like polyp, fibroid, old endometrial tissue, hormonal
imbalance (by implant itself) and pelvic infection
may cause brown to dark red bleeding/ discharge.
Kindly, consult with gynecologist and proceed pelvic examination with TVS scan to identify the exact cause. Take suggestive measures accordingly.
Till then, maintain genital hygiene. Good luck.