Thanks for using DoctorSpring.com for posting your query.
I have gone through your question in detail and I can understand what you are going through.
Yes you are right. The IM injections are ideally given on the upper buttock and the pain should appearon the upper buttock area. Further an injection is a painful process and its practically not possible to administer an injection without your knowledge.
Its unlikely that you have been injected.
Hope this helps,
In case if you have any further query, do let me know.
Dr. Srikanth Reddy