Been on birth control for about a week, started after my period ended and now i have reddish brown discharge, is this normal, how long should it last?

Possible normal: Some women have breakthrough spotting the first couple cycle packs on the pill, especially on the lower dose pills. However, check a pregnancy test to be safe and if it persists see your physician as infection another cause or a change in pill may be needed.

Likely normal: It is very common to have spotting during your first couple months on new birth control while your body adjusts to the new hormones. Occasionally, people will spot the whole month of a new pill. This should stop by your 3rd month, and if not, talk with your doctor about a different pill. And get seen now if any pain, discharge, fever, or foul odor.