If they hit a nerve you could be feeling it for months the not at the intensity you art feeling it now. I would use heat & ice (if there is inflammation ice will help). I would say at least a week. I also have a favorite ointment I put on bruises & sore muscles. Learned about it for horses but works amazing on people & pharmacies carry it now....called Arnica gel. I swear by it. Rub that on the whole upper arm where you got the shot. I swear by it because I whacked my shin on my dishwasher door & had a lump about 2 inches around & 3/4 in high. Put the arnica gel on it & watched the swelling go down.....t was shocked to see that....& never got black & blue either. Also put it on my face after major oral surgery. Me whole bottom part of my face was black & blue. The black & blue went away In 3 days. I do a lot of work on my farm & always getting sore muscles. Helps with that & cramps in my legs when sleeping. I have rubbed it on my legs & the cramps eased off to nothing. If I hadn't PERSONALLY had such good experience I would never recommend it. It could relieve this problem for you much sooner than just heat & ice & aspirin.....actually if you can take ibuprofen, it's a better anti-inflamitory than .

I have a retired pharmacist friend who has really helped me knowing what to use for what now I live alone I so appreciate his input along with natural healing things I've learned due to my horrible side effects to meds.