I'm 33 weeks pregnant and have very itchy breasts with a white head spots like rash in the cleverage what could this be please?

Fungal?: Due to the likely large size of your breasts and increased metabolism you may be experiencing increased sweating or warmth between te breasts with tissue macerarion and possibly a yeast infection. You shoul discuss with your gynecologist and keep the area clean and dry.

Folliculitis: Probably a folliculitis which can be like a heat rash, acne or even a yeast infection. See a derm.