Ive been suffering from brown discharge 24 hours after sex. I have recently had a baby 4 months ago. This problem happened then too. Any ideas what this could be?

Was the sex rough? Sometimes after having a baby it takes the cervix a while to get back to it's pre-pregnant state. The cervix is highly vascular, it has tons of tiny capillaries, and sex can sometimes cause bleeding. Also, it is possible that your cervix may not be entirely closed from having the baby.

Best thing for you to do would be to contact your doctor for a proper diagnosis.