Tea is fine, it dosent have to be decaffeinated. You would have to drink multiple cups of black tea before even reaching the amount of caffeine in one small cup of coffee. I drink English Breakfast or Earl Grey every morning, usually two mugs, with my OB's full approval. Then I usually have some Sleepytime (regular, no valerian) or Mint tea at night.
This! And the only teas you have to worry about are some herbal teas, since they can have a bunch of different things mixed in, so just make sure an ingredient isn't in there. I drink multiple types of teas daily and have yet to come across an herbal tea that has a "don't drink" ingredient on it.
As a side note: I recently tried Celestial Seasonings, Sugar Cookie tea. OH MY GOSH. I don't like things that taste like cookies (that is not a cookie!) but it's so amazing.