I been drinking chamomille herbal tea. Does that have any bad effect for my unborn baby?

No known ill effects. As far as we know, chamomille is totally safe to use during pregnancy. However, i would echo the words of herbalist christopher hobbs in suggesting one minimize exposure to herbs during the 1st trimester to err on the side of caution. But if you have drunk it during the 1st trimester i would not worry at all. See www.Babycenter.Com/406_is-it-safe-to-drink-herbal-tea-during-pregnancy_1246852.Bc.