Hi,
A headache is one of the normal, side effects, of many, many different drugs.
I suggest doing a little online research, using
http://www.google.com, type in levitra and reading about it. A good place is drugs.com
Then, I would talk with your doctor; tell him/her all about it; and get professional advice. Any prescription medication has side effects, and you should be aware of all of them. Don't visit the manufacturer's website, cause they will not tell you much about them!
Best of luck,
fredg