Help please flea problem :(

Helpppp!!!! Anyone please :( some how we've got fleas in our house my cat is a house cat and doesn't leave the building what so ever she's ended up getting fleas biting her to death and now the house is literally infested I hover every day my cats had monthly treatments of spot on and flea tablets and now we've tried the spray nothing is working we've got a baby on the way too I'm petrified she's gunna get bit as I'm covered in them which is not healthy for me either being pregnant any advice please :( xx