lo is 2.5 months old and still on level 1 avent nipples. she doesn't seem frustrated with them, but it takes her about 30 minutes to drink 4 oz.
I've tried switching her to level 2 (1+ months) twice. both times she takes the bottle down easily, but after she seems like she is in pain and her stomach is really bothering her.
this is a stupid ftm question, but can i just keep using the level 1 nipples?