The chance that your headache is caused by a brain tumor is very rare. You have not mentioned the duration of your headache, but if its few days don't worry too much. You can continue taking tylenol as and when needed. But you may want to consult a doctor if its still persisting.
Also do consult the doctor if you have any of the symptoms
-Nausea or vomiting
-Headache persisting beyond few days
-Visual disturbances or loss
Early morning headache can be a symptom of hypertension. So you may want to get your blood pressure checked too.
Hope this helps