Can you develop symptoms of naegleria fowleri after seven days. i woke up this morning with a stiff neck but no sign of headaches or fever?

Usually...: Usually the symptoms of meningoencephalitis caused by N.fowleri occur between 5-7 days after exposure but are usually significant for high fever, headaches, nausea, vomiting, light sensitivity, and in severe cases with seizures and confusion as well.

Yes but you would be: really sick. N. fowleri infection causes primary amebic meningoencephalitis which destroys brain tissue. Sx's usually begin within 2 to 15 days of exposure & may include sudden fever, severe headache, neck stiffness, nausea / vomiting, light sensitivity, feeling tired, confusion, loss of balance, hallucinations, seizures & death. REF: