With a sinus headache, you will often deal with post nasal drip, which is a collection of mucus in the back of your throat when you're lying on your back. you may also be congested. These symptoms are also typical of migraine. However, a sinus infection will last considerably longer, and if it becomes worse you may feel generally sick and even have a fever (with migraine you may feel like you have a fever, but you usually don't). Fatigue is common. you may also find that your mucus is thicker than normal and discoloured.
The pain in a sinus headache is usually localized around the eyes, and you may actually feel some tenderness.