Hiya Meggles~
Try not to worry just yet. I look at smear tests for a living so I hope the info I have for you will help you understand your situation.
First off, if it makes you feel better to go and have another smear 6 weeks after the previous one, please tell your GP. There is NO reason why it can't be done. If he/she gives you any hassle, simply find out where your trust's GUM (Genitourinary Medicine) clinic is, and make an appointment. Every trust has one and they will understand your concerns.
There are multiple reasons you might have an abnormal smear result. One common reason is some type of reaction to irritation. In this case the cells may show some signs of change without actually being abnormal.
Another common reason is an HPV (human papilloma virus) infection. HPV is a very common infection and has hundreds of subtypes. (Like different brands of something~fundamentally the same but slight differences.) The subtypes that are known to cause the cells to progress to cancer are called "high risk" and the ones that cause cellular changes, but don't progress to cancer are called "low risk".
There is a way of testing to see if you have high risk HPV present, but the NHS does not currently offer it. You can ask your GP to be referred privately if you want this test performed. (PM me if you want the names of labs that do it.)
With regards to frequency of smear tests, if you have an abnormal history you ARE entitled to smear tests every 6 months until 3 negatives in a row are obtained, then you will go to yearly for up to 10 years. The every 3 yearly thing is ONLY for people with a normal history.
I hope this helps and please PM me if I can help in any way.