DD is 4 months, but still using level 1 teats. I've tried changing to 2's a couple of times but she seems really uncomfortable - squirming, crying vomitting! Especially at the last feed of the day when she's tired. She takes 20-30mins to take 7oz with the level 1's, but there's no squirming etc with these. Does anyone else have a baby who hasn't moved to the next level teat at the recommended age?