I Had Sex With My Girl Friend.. Three Days Later

i had sex with my girl friend.. three days later i could see semen in her vagina .... is there chances of semen being visible in vagina after 3 days? my wife is very particular in hygiene and she washes her vagina with V-Wash everyday still how come i could see semen in vagina after 3 days... is it that she is maintaining relationship with someone else