discharge for the last 4 days and am not due?

Hi,
Welcome to ehealthforum.
If you have been regular with taking your birth control pill at scheduled time daily and have not missed taking any active birth control pill, you should continue to have protection. Chances of pregnancy also reduce if sexual contact/intercourse is timed to be during your infertile days. The brown discharge that you describe could suggest chances of ovulation bleed, breakthrough bleeding, hormonal imbalances, infections, etc. The exact cause can only be made out after careful evaluation. Consider visiting your doctor/gynecologist at the earliest for thorough examination and further evaluation to look for the underlying cause for the abnormal discharge that you describe. Treatment as needed (based on examination findings and investigations results) would be started to help you. Consider being in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle. If infective cause is detected, get your partner also treated simultaneously, and avoid having intercourse while being on treatment to prevent chances of re-infection. If you are still worried about pregnancy, use back-up protection if having intercourse to have additional protection against pregnancy.
Take care.