On birth control pills and have slight bleeding after sex right after and then next day but very light and not consistent. is this normal?

Bleeding: Bleeding after intercourse isn't normal , could be a sign of a vaginal irritation, infection or abnormality with the anatomy such as a polyp or fibroid... See your doc for evaluation.

Post-coital bleeding: You could have an infection or some type of cervical or vaginal irritation or a cervical polyp. Is your pap smear up to date? If this continues you should see your gynecologist for an exam.