2 week old feeding question. Advice please

[Tartyshoes]

My 2 week old DS hasn't settled into a feeding pattern yet. I know it is early and I am still feeding on demand. Soemtimes he will go 3-4 hours but most of the time it is 2 hourly. This is fine, apart from the tiredness!! However for the last few days he is having trouble bring any wind up. I have been using infacol but it doesn't seem to make any difference. He is having 2-3 (usually 2) oz of Aptamil 1 at each feed. Last night and today he has been being a little sick as well and really grouchy.

Could it be the formula? is he just settling down?

I know this sounds really trivial but DS1 was really settled and fed well as a baby. DS2 seems to be unhappy.

Any advice?

Have you considered reflux? Does he roll his tongue out his mouth as if he has a bad taste in his mouth? Most people think reflux is just a sicky baby, but they are not always sick.
The acid in their tummy makes them very grouchy and irritable at feed times.
If he arches his back away from the feed, seems to be in pain then perhaps consider it and ask midwife for help.
But trust your instincts, if you don't think something is quite right, mums know best..!