Red Raspberry Leaf Tea

You can usually find a blend in any large grocery store, or check a health food store. Red raspberry leaf is a time-honored tradition for pregnant women; it contributes to uterine health by strengthening the muscles (does NOT cause uterine contractions), eases constipation, and provides vitamin C and calcium.
Note: only one source (out of many) had a caution about red raspberry leaf tea, noting that it had caused spotting when used in early pregnancy. I have used it all through my pregnancy, but if you aren't sure it's safe for you, wait until you are further along before you drink red raspberry leaf tea, or ask your health provider about it first. 

Ginger Tea

You can find a ginger tea, pre-packaged, or simply make your own by steeping peeled, diced fresh ginger root in hot water, then sweetening to taste. Add a little lemon juice if you like. Ginger is safe and is one of the best ways to help ease morning sickness, indigestion, and flatulence.

Lemon Balm Tea

This one may be a bit more difficult to find, but a health food store will probably carry a lemon balm tea and an herb store may simply have dried (or fresh) lemon balm available from which you can make tea. Lemon Balm is wonderfully scented, very fresh and citrusy. It is a great before-bed drink, as it is very calming and mildly sedative, and may also help with indigestion.

Rose Hip Tea

As above, you may need to visit a health or herb store to find rose hip tea or rose hips, but it is well worth it. Rose Hips are very mild, extremely high in Vitamin C, and and have antioxidant properties. They can help ease headaches, dizziness, and prevent bladder infections. Rose Hip tea will be mildly tangy. It would be great in combination with lemon balm or citrus peel tea. (Citrus peel teas are fine during pregnancy, too.)

Peppermint Tea

Another time-honored method of relief for nausea, morning sickness, indigestion, and flatulence, peppermint tea is my personal favorite for those early, icky weeks when your stomach is heaving. It's easy to find Peppermint tea; any grocery store will have it. You can also make your own from fresh or dried mint. Try it without any sweetener, as sugar or honey can make nausea worse. Drink it hot or cold. During my last pregnancy, which was mainly in the summertime, I would make a big pot of peppermint tea, cool it off, and fill my water bottle with ice and tea. I took it with me everywhere, and it helped me actually eat and keep food down.