Am I allergic to Advil (400mg)?

I took it and then 12 hours later, my cheeks got red and so did my lips. This made me a bit confused because I don't know if it means I'm allergic to the medication or to the spicy snacks I ate a few hours after the pill. I thought it might have been the snacks, but I ate it again and didn't have any reaction for the first couple of times, just some very mild flushing of the cheeks the last time I had them. This made me afraid of taking Advil, so I don't know how to figure out this allergy. Any clues?