I would just go with plenty water (for the kidneys ect) and fiber. Don't use one of those quick fix colon clense body de-tox type things from the health food store or an info-mercial. They work too fast and can be a shock to your system if you know what I mean. You need a healthy diet at all times and nourishment. Please don't go to extremes while you are pregnant ok?
water, oh! and turmeric is one of the best things for you! it cleanses your systems and everything! its a spice it doesnt taste good but its AMAZINGLY good for you
Just lots and lots of water. Drink 8 big glasses a day. Make sure you are taking your prenatals