וְאִשָּׁ֕ה אֲשֶׁ֨ר יִשְׁכַּ֥ב אִ֛ישׁ אֹתָ֖הּ שִׁכְבַת־זָ֑רַע וְרָחֲצ֣וּ בַמַּ֔יִם וְטָמְא֖וּ עַד־הָעָֽרֶב׃
The woman also with whom a man shall lie carnally, they shall both bathe themselves in water, and be unclean until the even.
Mishnah Mikvaot
If a non-Jewish woman discharged semen from an Israelite, it is unclean. If an Israelite woman discharged semen from a non-Jewish man, it is clean. If a woman had intercourse and then went down and immersed herself but did not sweep out the house, it is as though she had not immersed herself. If a man who had a seminal emission immersed himself but did not first pass urine, he again becomes unclean when he passes urine. Rabbi Yose says: if he was sick or old he is unclean, but if he was young and healthy he remains clean.