Advice please

Earlier this month I took my hamster to the exotic vet (a little over an hour away) because I wanted to check if everything is okay with him also because he had shown some weird behavior sometimes so i was worried. The vet was really nice and professional and told me that he looked very good and healthy for his age (1 year and 4 months old i believe he is) which made me relieved. But sometimes randomly and not that frequently, he does a little cough/sneeze looking thing. And yesterday when i had him out and was cuddling a bit with him, he woke up and then yawned and i thought it was cute and then he yawned again and i thought oh he must be really tired thats cute, but then he continued to yawn many times and i thought he was maybe choking or had something stuck in his mouth but I couldnt see anything so i offered him some fresh cucumber and he enjoyed that for awhile and then he didnt do the yawning anymore. Today when i took him out of his cage he did that cough thing and then I heard him do a subtle clicking sound for a little bit but then it stopped and it wasnt loud, i had to hold him up to my ear to clearly hear it. I just dont know what to do honestly. Im going to call the vet early tomorrow and hope that she might just prescribe him medicine without having to drive all the way to the vet. Its going to be very hot outside tomorrow and my car doesnt have AC. He was also very stressed out last time during the car ride so i also just dont want to stress him out again like that. I dont know what to do. I know that respiratory infections and stuff like that gets urgent really quickly and the vet isnt open in the weekend so i have to do something about it tomorrow.