F is 8, almost 9 months old. He's been EBF and drinking pumped milk from a bottle since he started daycare at 3 months old.

About a month ago, daycare would tell me he was "fussy" with his bottle (usually only 1 out of 3-4 bottles), but he would drink around 12oz a day. 3 weeks ago, we bumped down to part time (2 days a week) and now he is flat out refusing a bottle. He'll drink 1 1/2 - 2oz in a 7-8 hour period. He also refuses when we try at home.

How concerned should I be? His diapers are still wet, he nurses for me (although now he's up multiple times at night), and seems fine overall. Everyone suggests that it's teething, but it's been so long and no teeth have shown up.

Do I wait it out and do nothing? Should I try a bunch of other bottles/cups? My mom told me to give him formula (what?! That made no sense!) I'm a little worried about when he start back at daycare 5 days a week in August.

P.S. I am going to a wedding in a week and we'll be apart for at least 2 feedings, so I want him to take a bottle then.