Girls, moms, please help! What could it be? Allergy, eczema or somethi…

Girls, moms, please help! What could it be? Allergy, eczema or something else? The baby is 3 weeks old. On the back of the head, under the hair, little pimples popped up. At first I didn't pay attention, thought that it was either acne popped up on the back of the head, or she got sweaty. Applied Sudocrem, tried not to cover her, went on a diet. But they got even bigger. What should I do? I am ahead of questions, we are going to the doctor tomorrow. It appeared on the weekend, so I couldn't go to the doctor.