Is there a way i can test if i'm allergic to aspirin? i want to try it for my headaches but not sure if i've had it before. tried everything else?

Doubtful: If you have never had Aspirin before , it is highly unlikely that you would be allergic to it given how rare true aspirin allergy is. People with aspirin induced asthma may however react to it on the first exposure but that's more a biochemical reaction than an allergy. But you have had a serious reaction to ASA in the past, then you must avoid it.