In early stage of hernia the lump may not be visible at all, but you may just experience sharp or dull pain and discomfort.
Try to do some life style changes and avoid activities that lead to increased abdominal pressure heavy lifting, straining during a bowel movement or urination, strenuous coughing and obesity.
When the visible hernia is getting bigger, more painful and can't be pushed back in abdominal cavity, surgeon should be seen as soon as possible.

You may have what is known as an incipient or occult hernia - basically a hidden hernia, one that shows no outward symptoms (i.e. a bulge). Not all hernias need operated on. There is a newer trend to hernia health care that is called "watchful waiting". This is basically keeping an eye on your hernia if you have no signs of pain, discomfort or bulging that could complicate matters. Do a google search for that. There is a website called the Hernia Bible that will give you guidelines on how to incorporate watchful waiting into your life - along the lines of suggestion given my MandMs - basically lifestyle changes. If you haven't done so yet, a second opinion from a surgeon, along with corroborating scans, may be a way for you to verify if the CT scan was actually correct. Dynamic ultrasounds and dye-contrast MRIs may be other imaging options. Personally, I believe it never hurts to get a second opinion.