YES!
There are a few ways of going about things if you do deregister-but firstly I have to tell you that your parents must send in the proper letter to free you from school-I'll bump up the threads about deregistration for you shortly.
We deregistered our children eight years ago and have home educated them through their teenage years.
Like us you could be very informal and follow your own interests and then go on to FE college and do GCSE and/or A levels, post 16 as our son did (and achieved very good results)
OR you could use a distance learning package such as the ones offered by Oxford Learning, The National Extension Collegeor The Little Arthur School or you could go to the AQA website, download the curriculum, study it yourself at home and find a place to enter as an independent candidate to take the exam, this is the cheapest option, but I believe finding the exam centre to take independent candidates can be the most challenging-although some independent schools may be coming forward to help in this area soon. Your present school may even be open to allowing this, you never know.
OR you could skip GSCEs and A levels altogether and go for an OU course. This is the route increasingly being taken by some home educators. You could find subjects you are interested in and start on a university level course right now!
Our youngest daughter started an OU course aged 15. The feedback and support she has received has been brilliant and we would highly recommend it as an option.
We have several friends who have followed this path and then applied to go to 'bricks and mortar' Uni aged 18 with degree level qualifications to prove their ability to study independently to the required level. Universities seem to appreciate this-and there is one well known top uni that apparently reserves 60 or so places a year on it's science courses for applicants with OU qualifications.
We know of two home educators who are studying law at Oxford by taking this path-and neither have any GCSEs or A levels.
Lastly I would strongly recommend you get hold of the book Teenage Liberation Handbook :How to Quit School and get a Real Life and Education by Grace Llewellyn. Although it is written for American teens to read, the ideas and themes fit well with home educated youngsters in the UK. It is this book that really showed our family the freedoms that home ed could bring.
Does that answer all of your questions?
Happy to help if you have any more.