Carmen Ewald answered 8/9/2009 If A Boy Doing Intercourse With A Girl Nd Put His Sperm In The Girl Virgina For One Time Could The Girl Get Pregnant? When the girl is in her fertile days, yes. Otherwise, nope. When is a girl fertile? The point is day 14th of the period (counting from the beginning of the last period), span it 3 days before and 3 days after. (Memek ABG)