Girls, could you please tell me something?

Girls, could you please tell me something? My daughter is 1.5 months old. Today morning and yesterday afternoon she had a temperature of 38.5. She called the doctor who checked, her throat was clean, nose was clean, there was no thrush, no stomatitis, what could it be? I know that about teeth is premature to say, but I suspect them, why do I think so? The lower two are swollen, and she's always putting her hands in her mouth even when full. We give her a pacifier, but she throws it with her hands, which makes it constantly fall out. My son at 3 months already had 2 lower ones. We sleep poorly.