move up a nipple size?

UAbride31007

For the last week at daycare, DS has not been doing well with the bottle. I nurse him at 8 before we leave, he gets a bottle around 10-10:30 and then I nurse him again at around 12-1 (I work at his daycare) and he gets another bottle around 4 after his nap. This past week he has only taken 2 of his 4 oz in the AM. In the afternoons he usually takes all 4-5 oz but a couple days only took 2 oz. His teacher said he just plays with the nipple but is perfectly happy during the day.

I've had several moms they had the same problem and have solved it by going up a nipple size. However, everything I've read says to keep BF babies on the slowest flow nipple as long as possible. I'm thinking he's going through the 4 month wakeful as he's been up at 3 AM nearly every night this week after STTN since 9 weeks. I have told them to make sure his bottles are really warm because that's how he likes it and they said they do. He has enough wet/dirty diapers and weighed 14lbs 3oz on Monday at the Dr. (15 weeks old) so I'm not terribly worried but just a little concerned. TIA for the advice