it sounds like you're thinking too much about your pregnancy & little anxious? maybe u can try meditation.
get some relaxation CDs and focus on your breathing. listen to yourself breath. when your mind wonders away, & you suddenly realize it (which you will every minute), just bring your mind back & focus on your breathing again.
or you can try this relaxation technique: focus on your breathing then tell yourself to relax your head, when you feel that your head is realx, go on down to relax the tiny muscles around your eyes, relax your nose, relax your mouth, you might let your mouth droop a little, then relax your jaws.... then relax your neck, shoulders, top of your back.... until the tips of your fingers, and relax your tummy, your hips, and your thighs until you reach the tip of ur toes... all the while taking about 3 seconds to relax each part. so it takes like 10 mins to do the whole process. if your mind wonders off midway, start all over from the top of your head.
let me know if it works!