Not eating during the day!

It started on Saturday afternoon that my LO does not want to eat! She would only drink 2oz out of her usual 5 and leave it alone. She will fuss and cry if I try to make her drink more 😩 She will wake up 3x at night these past three nights to compensate. She has a doctors appointment later today, so hopefully he can tell me what’s going on??! Anyone else have a 4 month old that doesn’t want to eat all of a sudden?? What has your pediatrician said?? Could it be because of teething?? I’m so worried😞

*Update* Well her pediatrician said it’s due to teething. She is still gaining weight, but I need to monitor her for 2 weeks and see if she will go back to her normal eating or lose weight and feel sick in order to go back and see him.😕