how do they mate and do they just mate on their own? how do i know if one is pregnent or even if they have mated they spend a lot of time in there cave even at night....

Scorpion mating can be quite a complicated process.

First the male finds a female, using the pectines to trace the female's pheromones.

then he starts the courtship dance, called the promenade à deux which basically involves the male juddering to start, to alert the female of his presence and willingness to mate.. then the male grabs the the female by the pedipalps (or the arm, if he doesn't do it quite right) and leads her on what resembles a dance. In most matings the male also gives the female a "sexual sting" and may do other things, like chelicerae "kissing".

here's a video on the process; http://www.youtube.com/watch?v=UX-jk1H2aDM

the dance is the male trying to find a suitible place to deposit his spermatophore, usually on a flat, even surface. Then he leads the female over it and hopefully the female will accept it. Then, depending on the species, the male may leg it ASAP, or may just hang around for a bit depending on how sociable the species is.

You won't be able to tell if the scorp is preggers right away, it'll take a few months. Gestation can last from a few months to over a year, depending on the species and conditions in which it is kept.

wow lots of info saw the video thanks alot...