Anyone else do shift work?

I started a new job about 3 weeks ago (7a-3p) and will be going to 4th shift next week (7p-3a) for more training. I will be 9 weeks on Sat and no one at work is aware of the pregnancy. I am already nervous about the drastic change, let alone being pregnant. I am already exhausted and can't pound caffeine to keep me awake while I adjust. I'm also worried about the physical and mental stress upsetting my bodies natural rhythm will put on the baby. Any recommendations or suggestions would be appreciated!