Predisone

So I went to the ER last night for a very severe asthma attack. They prescribed me a very high dose of predisone and the pharmacist scared me by saying I absolutely can't take it while pregnant. But it's the only thing that ever has worked for my asthma in the past. I call my dr at 9 but was wondering if anyone else has gone through sever asthma while pregnant or taken prednisone and turned out ok? Please need some feedback. ?