I have had mild vaginal bleeding/spotting for the last for weeks. Its all brown stuff not red. I have an implant and have been having normal periods?

Vaginal bleeding. Vaginal bleeding or spotting can always indicate the possibility of pregnancy, even an ectopic pregnancy and despite your implant, you could be pregnant. So do a home pregnancy test. There are many factors such as fibroids or polyps which could cause spotting, but lack of ovulation or thin uterine lining could be related to the implant. Check with your md.