Hello, I need some advise.. I have a two month old boy.. A week ago he was starting to feed 4-5oz. every 3-3 1/2 hours. But mostly 5oz. especially during the day. But this week he has gone back down to 4 oz. His bowel movements have also changed. And so has the consistency at times. He has a bit of flems. But yesterday he spit up the first oz. I gave him in two feedings. After that, he has been fine. What could it be???