chest infection when pregnant!

I've been sick for the last two days with a really bad flu and this morning I can feel that it's gone to my chest. I have bad ashma so whenever I get sick I always end up with a chest infection! Obviously because I'm 5 week and 5 days pregnant I can't take any antibiotics, but because I have bad ashma my chest infections are usually bad, will this harm the baby? I have to work tonight because I took yesterday off sick already and need the money :/