Formula feeding

So my husband had our 1 month old today who is usually taking 4oz every 3-4 hours during the day abd will go 5 hour stretches at night. Today while I was out, he started giving him 5 oz. I just feel like that is so much for a 1 month old. He isn't fussy after and isn't spitting up. He was 8lb 9oz when we was born. Our first was 6lb 9oz when born and I don't remember eating that much until much later. Thoughts?! Am I over reacting?