I have always had regular periods...I had a injection of Kenalog for Bronchitis on Jan.29, 2008 and I have a had a non-stop period with the exception of a few days ever since. My doctor did not inform me of any side effects even though I asked if there were any side effects, he told me no side effects. If he had told me it can cause menstrual irregularities, I would have never agreed to have this awful drug in my body. I am furious that now my body is all screwed up from Kenalog..we are trying to get pregnant and that is an impossibility at this time because of my irregular cycle. I called Bristol Meyers and they said it should go back to normal in a few months. This is a very very strong steroid and patients should be advised of the possible side effects. I will never ever take this drug again...