It's essential that you keep asthma under control in pregnancy, which means continuing to use your inhalers, since the risks from uncontrolled asthma are greater than any risk from taking asthma medication. If asthma is uncontrolled, it can mean that not enough oxygen gets to the baby, leading to a low birth weight or other problems. One of the best ways to control asthma, in addition to taking medication, is to avoid asthma triggers such as pet fur and dust mites. Use air filters, vacuum often, and damp dust, and use duvet, mattress, and pillow protectors. Sometimes, pregnancy reduces the severity of asthma, but if you feel wheezier than usual, talk to your doctor about reviewing your medication.
Homeopathy works on the principle of treating like with like to stimulate the body's natural healing mechanisms. There has been debate about the efficacy of homeopathy and the scientific opinion is that there is insufficient evidence to show that homeopathy has any effect beyond that of a placebo. But talk to your doctor before using any homeopathic products or remedies during pregnancy, since homeopathy is an area of complementary and alternative medicine that's associated with much debate and scientific controversy. If your doctor gives you the okay, a certified homeopath may be able to provide treatment.
The US Food and Drug Administration does not regulate herbs and other dietary supplements, and there's not much research about the health effects of many herbs on pregnant women, so it's best to avoid them while you're pregnant, including herbal teas. Decaffeinated black teas are your best bet, but if you want a fruit or ginger tea, read the ingredient label on the package carefully to be sure that no herbs are present. If you want to use an herbal remedy, talk to your doctor first.