You can visit the doctor for free in the UK, although you may have to pay an amount towards a prescription. You need to register with a doctor in your area as soon as you get there. Check your local phonebook for details. If you get sick and haven’t registered with the doctor – not to worry – just pop along and they will register you while you’re waiting. Contraception is free in most forms.
Medical insurance is still advisable though, in case of grave illness or a major accident. You may want to get treated before the NHS is able to schedule you one of their operations. In this case going privately can be hideously expensive. The insurance money is really money well spent.