Baby rash

Hello everyone today I discovered my baby of 1 month and a week has theses little bumps on her back what can the be from? I called her pediatrician and they told me could be what I was her clothes with or a newborn rash but I wanna know have anyone else seen theses ? I really think they are heat rashes but idk but she definitely really fussy omg 😥😥 please help and if anyone of you guys have information what can I use on them