Help 😭 Long fever

Has anyone or kids ever had a fever for almost a week? My one and a half year old started a fever Sunday, he was pulling at his ears so I took him to the doctor. Every was good "just teething" Wednesday morning it spiked to 104 so we went back to the doctor, they rechecked him and even did blood work and found nothing. They said to come back Friday if it doesn't go away and he still has it this morning 🤒 has anyone experienced this? I'm a FTM and so nervous 😔