it is correct in that people say it and no one complains (well, almost no one). It is not strictly correct (supposed to use well not good, well is an adverb and good is an adjective), but we don't care. And since we do not care and it is extremely common, I call it correct, or rather I will not call it wrong. How can it be wrong when it is said by so many and gives the intended meaning (people understand it)? That is the entire idea of right or wrong in language: is it used and does it carry a specific meaning that all understand? Screw the grammar pedants.
So, sure, you ought to say "I haven't been feeling well lately" but people mostly simply do not.
Answers & Comments
Nope "I haven't been feeling well lately" is correct.
Even though "good" is used by many people technically its incorrect
Technically, 'well' is correct, but many people use 'good'.
Yes
it is correct in that people say it and no one complains (well, almost no one). It is not strictly correct (supposed to use well not good, well is an adverb and good is an adjective), but we don't care. And since we do not care and it is extremely common, I call it correct, or rather I will not call it wrong. How can it be wrong when it is said by so many and gives the intended meaning (people understand it)? That is the entire idea of right or wrong in language: is it used and does it carry a specific meaning that all understand? Screw the grammar pedants.
So, sure, you ought to say "I haven't been feeling well lately" but people mostly simply do not.
works fine
In American English, it should correctly be "I haven't been feeling well lately."
It's correct in American English. In British English we would say 'I haven't been feeling well lately'.
It should be "I haven't been feeling well lately".