The Question: “Is it true that you can’t get pregnant if you get up and jump around after sex?”
My Answer: No.
An Addendum From The Fabulous Erika: Like salmon, sperm are perfectly capable of spawning by swimming upstream.
Spelling It Out in Plain English: You can still get pregnant if you jump up and down after sex. If you don’t want to get pregnant you need to avoid vaginal intercourse, use contraceptives, or both.