Firstly, you need to be evaluated for the cause of your irregular periods
. Secondly, implantation
bleeding is a fresh bleeding and is usually pinkish and is seen around 10 days after ovulation; brownish discharge indicates old bleeding. You may be having a breakthrough due to hormonal
disturbance. Yet, as you had intercourse during the fertile period, you should take a pregnancy
test and see your gynecologist for further suggestions. Take care.