Help!! Mould! Anyone from the UK?

Hiya I am 12 weeks pregnant and ever since I moved into my 1 bedroom flat a year and a half ago there has been a horrible black mould in the bathroom, 3 walls in the bedroom, 2 hallway walks and in the kitchen! We have cleaned this 4 times now and it just keeps coming back! I don't know what else to do! Has anyone got any advice? Can the council move me? I am really worried about this!