Im having my 3 epidural for lower back pain within 8weeks do i run a higher risk?

Yes: Epidural spinal injections (esi) are established by research to be potentially beneficial for patients with radiating nerve pain from nerve compression. For patients with spine pain without correlating nerve symptoms, there is little scientific evidence that there is potential benefit to esi's. Therefore, esi's are not indicated for spine pain without symptomatic neurological compression.

Yes: Complication risks are cummiuative the more.

What Risk?: Depends on what risk you are speaking of... Generally there is no major risk in the long term, in the short term you could have steroid side effects, but assuming you have been ok with the past 2, you maybe ok with the 3rd one. I would be hesitant to consider anymore given the 3 in a row. As long as you have relief, i wait at least 2 months for future treatments and maybe consider surgery.