There is no evidence that bleaching powder can really harm in utero baby. Moreover, you have just inhaled bleaching powder. I think your baby should be fine. Still, you must consult your gynaecologist.
Same thing happened to me when I was pregnant .. it was really scary. I try to crack the window or put on the exhaust fan. You can ask your OB/GYN to be certain if that helps, too.
C~
The bleach exposure will NOT in any way hurt your baby. DON'T WORRY! You have to be careful you don't get a lung infection, because the antibiotic used to treat the infection might harm your baby. Take it easy for a few days until everything heals, which it will.