Reoccurring ear infection?

My 13 month old had a "really bad" double ear infection according to his pediatrician. He was on 6 days of oral antibiotics and went back for a check 4 days after the antibiotics started and she said his ears looked much better. Anyways he ended the antibiotics two days ago and he's started waking up in the night again and being very fussy.. today he was crying in pain and inconsolable again until he got ibuprofen. We suspect his infection has returned somehow.. anyone else experience this?? We made an appointment to go see an ENT specialist for tomorrow morning but tonight is going to be rough 😞 we are so exhausted from both the kids being constantly sick which I'm sure most parents are feeling right now but the thought of him going on another week of antibiotics makes me want to cry.