I am writing some novels and they have some dialogue that has strong feelings. Here is an example:

"Oh My God, I am going to have a child"

I now have a comma there and it is okay and other grammar checkers including the word accept it.

Should I really use an exclamation point after the "Oh My God"?

My novels have only 3 main types based on punctuation and feeling and some hybrids.

I have some interrogative.

I have a few imperative.

Most of mine are declarative or interrogative or a hybrid of any 2.

For example "Can you make some mexican food please?" is interrogative because it is a question but it is also imperative because there is a command in the question.

When should I use exclamatory sentences in my novels? I only use them in dialogue but you know what I am really asking is which words are best followed by an exclamation point rather than a comma or semicolon and the rest of the sentence.