Thanks for the query.
According to your description there is possibility of post coital tears leading to inflammatory reaction or there could be some infection.
So you can take sitz bath which can give some relief.
You can use on counter drugs like candid
gel etc. and analgesic
and anti-inflammatory oral tablets.
But if the symptoms persist even after using them, you have to consult gynecologist.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429