Possible reactions to foods

I'm not sure what's going on with my body. I have a suspicion that it MIGHT be the ginger ale. Or the combination of ginger ale and cranberry juice.
Allow me to explain. Yesterday I poured myself a glass of cranberry juice and put in some ginger ale. I've had it plenty of times before if not recently. Half way through the glass I got a bad headache in the back of my skull. I slept it off and all was right again. Well, as right as I usually am.
Anyway, today at dinner I poured the same thing. And again, half way through I get the headache. Different time of day both times and nothing else in common.
Drinking them apart hasn't had any ill effects so far. So I'm wondering if it is the drink or possibly something else. The only thing I know for sure is I'm not going to drink it again.
Things were so much easier when I mixed Malibu with my cranberry juice! LOL