So I need some advice. My son woke up a little after 7 this morning and has only drank about 6…

So I need some advice. My son woke up a little after 7 this morning and has only drank about 6 ounces of formula today. He ate lunch (he has been on baby food for awhile now) and ate half of the container but still refuses a bottle. I know there isn't anything to worry about until he won't drink for awhile but dehydration is stressing me out. He's 5 months old and almost 18 pounds. He's a big boy and drinks a lot normally.