Does sperm live in water, and if so, how long should a woman wait before entering the bathroom after a man?

Obsessive whispering (waswasah) is a serious disease, so avoid these whispers and pay no attention to them. What you mentioned about this last whisper has no basis in reality, for pregnancy only occurs when a man's semen reaches a woman's womb. Beware lest Satan, through his whispers, drives you to delusion. Turn away from these whispers and live your life normally.