Is there any sexual position in which there is no risk of getting pregnant?

Absolutely not!

There is no such thing as a pregnancy-safe sexual position.

You can have vaginal sex in every possible position—lying on your back, lying on your belly, lying on your side, kneeling, standing, on one leg, upside down, or any other way. 

If you and your partner aren’t using any protection and his penis enters your vagina, you are at risk of pregnancy!