I don't know, a lot of these "unsafe in pregnancy" herbs just haven't had any testing done to determine if they're safe or not. I would assume that most- unless they're known for things like causing uterine contractions, etc- would be safe in small quantities. I'm really into lemongrass tea these days, which is untested for pregnancy so I just drink small amounts (1-2 cups a week tops).
You can try red rooibos tea (I can't STAND it, but a lot of people love it) because it's considered useful in pregnancy.....can't remember why, though. Even other fruity blends- blueberry, lemon zinger, raspberry thriller, etc. I'm really loving my decaf chocolate mint tea and my cinnamon vanilla spice tea. I love chai (decaf or otherwise!) with lots of steamy milk. A lot of tea companies (like Stash- do you have that there?) have come out with their seasonal teas, some of which are really really lovely. Sugar plum spice is amazing and I buy like, 10 boxes during the holidays to last us through the rest of the year. Also can't go wrong with staples like peppermint.
You could brew your own teas with nettles, alfalfa, of course red raspberry leaf, maybe a bit of lemon balm or peppermint leaves thrown in for flavor. Rose hips are a mellow almost berry-like flavor that I find very nice and I think they're high in vitamin C to boot.
Just find your favorite health food store and browse their tea section. Ask in the supplements section what is afe and what isn't, they'll have lists there. That's what I do :)
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