Hi good evening Thnxs for your question White discharge immediately after unprotected sex may be due to semen ejeculation into vagina. That was liquefied and come out as white discharge. So don't worry about this kind of discharge. But if u have whitish frothy discharge with itching and foul smell. Than u should consult Gynecologist. And better to use contraception to prevent unwanted pregnancy. Condom is best contraception for both of u. Thnxs