Smelling salts/ammonia

Relief at last! My migraines begin with uncontrollable yawning. I used to think the yawning was a migraine symptom, but I now believe yawning triggers the process of sinking into a migraine. I was explaining this to a friend, and when I said "sinking into a migraine" I pictured one of those old movies when women would swoon into a faint and then be revived by smellling salts, which contain ammonia. I didn't even know if I could buy it, but they sell it because athletes use them. They are not too expensive, but as often as I yawn, I would need lots. I bought a bottle of ammonia and put some in small shampoo containers you get in hotels so that one is available anywhere I am. I used to dread reading at work or riding in a vehicle because both make me drowsy and start my uncontrollable yawning and "sinking into a migraine" I find that peppermint tea also works to control the yawning, but it's not as quick and convenient. The quicker I abort the yawning the better I can prevent the migraine.