I am 100% sure that christa is prego.
1. In episode three when lee climbs the ladder, you can hear omid say"a group of guys is just what we need" then christa says its not and then omid says " WHAT ABOUT WHEN". Wink wink, HE'S TALKING ABOUT THE BABY. AND CHRISTA TELLS HIM TO STOP IT.
2. When lee digs up the dog in episode 4, christa vomits and says its just the smell but omid says in his opinion it's something else, THE BABY.
3. When watching the video in Crawford of the doctor telling the lady in the video,Anna corea, she has to have an abortion, CHRISTA LOOKS AWAY AND APPEARS TO ACT AS IF SHE IS HIDING HER PREGNANCY.
I know this could just be her being sad about how Crawford was and the lady as she states as a possible cover up when lee questions her looking away "what kind of place was this" but if you look at it carefully the evidence is there. Don't criticise me because it is my opinion. Please post yours.