Not quite. You can write this either as a "second conditional" or "third conditional" depending on the situation.
Second conditional: "If you were to ask me, I would say no."
(Or "If you asked me, I would say no".)
Third conditional: "If you had asked me, I would have said no".
Many native English speakers use conditional sentences incorrectly or "mixed conditionals", so you may hear examples that deviate from what I have written here.