There is an unusual ammonia smell during the pregnancy. This is due to sexually transmitted diseases (STDs) and urinary tract infections (UTIs) that cause the vagina to smell unpleasant or odd. Early pregnancy with a fishy smell is a sign of a vaginal infection called bacterial vaginosis. If the discharge is cottage-cheese-like consistency, it is called a yeast infection. The pink, brown, and red color of the discharge is a sign of infection. Heavy bleeding during pregnancy, is also a sign of ectopic pregnancy or miscarriage.