Are all sperms killed by washing hands with soap? Can I be pregnant if I touch my vagina (not insert finger) with wet finger after washing it?

No worries. A good washing with water will do just fine in rinsing away sperm. Soap is optional, but using soap is ok too. That said, many things are possible in life. Couples having sex should always be ready to be married, settled down, and with stable jobs that provide health insurance (a cute, surprise baby has just as many doctor visits as a planned baby).