I can get both migraines AND sinus headaches, which require different medications. It can be tricky to figure out which headache it is since migraines can also affect your sinuses, and both can make you feel nauseous.
So. . .one trick I learned to figure out which is which is the cold/hot test. If a cold compress feels better, it's probably a migraine. If a hot facecloth feels better, it's usually sinus. This may not be true for everyone, but it helped me. So I wanted to share.
One other clue, if you move and feel a worse throbbing in your head, it's likely migraine. Hope this helps someone.