If using herbs you will need to be careful which ones you use and in what amounts as many affect the female reproductive system. Calendula (Calendula officinalis) is one that has no contraindications for pregnancy. It is also a traditional remedy for morning sickness. A friend of mine would eat crystalized ginger (Zingiber officinalis) and said it worked great. She prefered the regular crystalized ginger to the REED's crystalized ginger as REED's tended to be too potent. It also calms the stomach/stomach acid and aids in digestion where antacids, like tums, destroy the acid in your stomach which causes digestive problems and also causes your stomach to produce too much acid.
There is also a point on the inside of the forearm, 3 finger widths up from the wrist, that is used for nausea. Just press on it when you feel nauseous. It is the same point used for the motion sickness bands. You can get a couple of those, or just a rubber band or string with a bead on it, and wear them on each arm. They are great if you have it all day or at random times, especially when you are at work and can't stop to drink tea or eat something.