Girls, advise me from experience, today the little one started vomiting…

Girls, advise me from experience, today the little one started vomiting after feeding since 10 am. Everything she ate returned back. She asked for breast again, and it returned again and so on in a circle 4 times. We're breastfeeding, we're a month old. She doesn't seem bothered by this, now she's sleeping, there are no temperatures. What should I do?