Had cortisone injections 2weeks ago in my lumbar area. Today I was scared and going crazy. I felt like I was going to get my period but I'm 57 and haven't had a period for 14 years. Sure enough I started a light bleeding. I was never informed of any side effects at all. Thank god I decided to look this up on the internet and found out this can be a side effect! So I will be letting my back doctor know about this when I see him in a few days.