In Chinese traditions, it is commonly known that the first three months of pregnancy are the most critical. I think western medicine will echo this too because the baby is just beginning to develop most of the critical pieces and there can be lots of instability. You will too often hear people announce their pregnancy after the 3 month incubation period is over and be cautious of what they eat.
Here is a straight forward guide and list of soups safe to consume during pregnancy. The basic concept of the Chinese soups is that none of them are extremely cooling, healing or potent in herbal additives. Enjoy!
Black Silkie Chicken with Vegetables and Chestnuts
Chicken Herbal Soup
Fish Maw with Seabed Coconut and Pork Bones
Fish Tail Soup with Lily Bulb and Carrots
Ham Bone Sour Vegetable Soup (The sour soup will probably really hit the spot in your early months)
Orange Vegetable Fish Soup
Papaya Fish Soup
Pork Bones and Arrowroot Soup
Pork Bones with Lotus Root Soup
Red Dates and Young Coconut with Fish Tail Soup
Seabed Coconut, Carrot and Corn Soup
Tomato Fish Soup
Tri-Coloured Pepper Vegetarian Soup
Turkey Bone Sour Vegetable Soup
In general, I would recommend fish soups. Although be careful of not using fish that are too large (due to the increased level of mercury in larger fish compared to smaller fish).