My three and a half month old doesnt want to drink her bottle ..?

she hasnt been too fussy, just a little bit but not more than normal, shell feed, and shell do fine with the , but i dont make enough milk to feed her milk exclusively, so we supplement. but since last night around 2am, she hasnt wanted her bottle at all, shell push it out and fussy and cry when i try to give it to her, ive tried a bunch of different and bottles but she just wont take it. she usually loves her bottles, so im not sure what the matter is. she doesnt seem sick, no fever, no vomiting. shes slightly congested but thats about it, and shes normally kind of mucusy. im afraid shes not getting enough to eat. what should i do? has anyone experienced anything like this before? im getting a little worried