Scarleteen

Why doesn't fingering with Precum on the finger pose as any real risk (even during ovulation) ?

Because sperm are delicate, and transferring them from place to place (a penis to a finger to a vagina) damages them and disrupts the environment that they need to survive. You can read more about what's needed for pregnancy to happen here: Human Reproduction: A Seafarer's Guide

So that means sperm picked from under wear and transferred to the finger then to the vagina have an almost zero percent chance to cause a pregnancy

You got it right.

And does precum have sperm in it if the guy has not ejaculated for about a day and has urinated after wards

The honest answer to that is maybe. You can read about why that is here: http://www.scarleteen.com/article/advic ... _pregnancy