Baby just wasn't eating enough for weight... Stuck at 60mls per feed when it should be 120ml according to baby's weight etc etc.... We noticed one of our teats was dripping when none of the other size 1s were.... And baby always consumed more from this teat.... So I ordered the next size (2) and baby has just taken their first full 120ml feed! But the boxes say wait till 3 mths... Have I BU?