I am 19 year old and I recieved a series of three epidurals of k...

I am 19 year old and I recieved a series of three epidurals of kenalog for a herniated disk. So far it has relieved pretty much all of my pain, but periods are completely unpredictable. Before I started the series, my periods were regular. I had just finished my period the day of my first injection, one week later I started my period again. Needless to say, I was a little shocked ...not to mention that it went on for nearly three weeks. I have been off of it for about two weeks now, but I am five days late (and not pregnant). I never know when to expect it now. I am a little upset that my doctor never mentioned this side effect to me!