Can you find out your pregnant with 4 positive pregnant test in less then 20 hours after sex? or does this mean i have to be further in my pregnancy?

Yes & Yes: One can have a positive pregnancy test hours after having sex, which means she was already pregnant many days earlier.

Unlikely: The urine pregnancy test may not show positive until 1-2 weeks after the sexual activity. The pregnancy test looks for HCG or human chorionic gonadotropin- which comes from the placenta. The test isn't positive until the placenta starts growing.