What i can i do to keep my headaches from becoming migraines?

when i get a headache it quickly grows into a migraine before the medicine can kick in and work. what can i do to prevent them from becoming migraines. they so bad sometime that they make me sick and i can't do anything but sleep in hopes of the pain lessening. i do take migraine medicine to help but sometimes the pills don't even work. any advice is welcome.