I had a couple about 7 years ago. I was in the US at the time and same thing, had an abnormal pap, waited 3 months, retested, still abnormal so recommended a colposcopy. It was done right in the dr's office with a little local anesthesia, delivered by what can only be described as a spray can with a long hose. It was fairly painless. It felt like a little pinch...
As for the results, the test showed that they were not cancerous or pre-cancerous cells. So they were most likely one of the 30-something strains of HPV, but not one of the cancer causing strains.
I ended up having more abnormal paps over the next year (I was getting tested every 3 months) and another colposcopy, with the same outcome. Since then I haven't had an abnormal pap at all. It's been about 7 years now. So whatever was causing the abnormal cells (HPV?) cleared up on it's own. The dr's I have had since the colposcopies, seem very relaxed about the history and happy with the 7 years of normal paps.
Try not to worry. I remember being a ball of nerves and researching everything on the internet and being petrified about cancer. In my circle of good college friends 4 out of about 10 of us have had colposcopies and nothing has been wrong. Good luck!