Zpack during pregnancy?

I am almost 11 weeks pregnant. I have bronchitis and asthma. I dont watn to take the zpack that they have prescibed me. They said its safe but I just dont feel comfortable taking anything, but after having bronchitis for a week now and just treating it with my inhalor and vicks vapor rub its obvious I need this antibiotic. Could the zpack harm the baby? does it have any side effects for the baby? with my first pregnany I didnt have any issues like this so I didnt need any meds. Thanks so much moms!