Whatdouneed

So it's been a month since since my first canker sore on tonsil. Doesn't hurt very mild discomfort. So I noticed today another one bigger than the first. Getting allergy shots for re occurring sore throats due to post nasal drip.. Or rather just the left side of my throat.. Never the right side unless it was strep. So needless to say the canker sore is on my left tonsil. My shot therapy is in the once a week dosage and I happens to get it yesterday. Not allergic to any foods so my shots don't contain any food allergens, just grass weeds etc. Is there any way that I am getting these canker sores because of my allergy shots? Any help would be great