Asthma Problems During Pregnancy

I have had asthma since middle school and have not had a real problem for about ten years until december. I was 25 weeks pregnant and could not breath, I went to the emergency room and was admitted in the hospital for three days. While in there I was seen by a lung specalist who recommended changing my medication from serevent to advair and singulair, as well as steroids and a antibiodic for several days. I asked several people, ob, nurses, regular family doctor, and even people in nicu, what the affects would be for my baby and everyone said that at this time I need to worry about myself staying healthy and strong for my baby. I decided to take the new medications and currently am taking the advair and singulair. With my last appointment with the lung spec. I asked about breast feeding with the new medications and he said that the advair would be fine, but check with the ob and pediatrican about the singulair. I spoke to the ob who said it was unknown and then today I spoke to the pediatrican who said singluair passes through the placenta and I should not have been put on it. He has suggested weaning myself off. I will not be taking it anymore, but no one is telling me what this may have done to my baby and there is nothing on singulair's website. Please tell me what may have been done to my baby?