please check your scalp , pimples are very common if you are having dandruff.

Hi!! Drink a lot of water; it may sound very repetitive and cliche but mind you increasing your fluid intake will not only help you with digestion and blood circulation, maintaing your pH levels but it also will be a great benefit during your entire pregnancy. Further,  add some jaggery and lemon in your diet. Also use good quality face wash and face creams.