We have also moved out of a place with black mould on a part of a ceiling. It was partly due to possum wee seeping down from the ceiling cavity above (ewww!) so it also stunk. I used to just get a mop, dip it in water/bleach, and reach up and spread it around. Bleach isn't too harmful for preggy women and using a mop was safer than climbing a ladder. It worked ok. sometimes needed two applications.