Confessions of a Cat Breeder

i recently moved in with my mom temporarily and we both have cats. she has a oen year old male maine coon and a two year old male orange tabby and mine is an eleven month old female grey striped tabby. she went into heat and we had all sorts of problems. rajah, the orange tabby, fell in love with Guin, my cat(Lady Guinevere- ironically we have a neighbor cat named Lancelot ), and mowgli, the coon, didn't like that at all. he kept attacking her for no apparent reason. we kicked him outside to see if he'd settle down. two days later he disappeared and we haven't seen him in almost two weeks. but my main question is - how do i tell if my cat is pregnant??? what kind of behaviors should i be looking for?? she does sleep a lot more than she did before rajah got a hold of her. and she has calmed down a little bit, but that could just be because she has a friend to play with and chase around the house. i'm confused. and do you think we'll ever see our "mowgsters" again??