It's a mess, Clarion. Even long standing qualified electricians argue over interpretation of current regulations.
For a start, the Regs are different for England and Wales.
Also, altering or extending a circuit in a "special location" (most commonly bathrooms and kitchens) IS notifiable, and must be done by a "competent person".......... that is until recently, when the "competent person" bit has been re-defined. Actually, only the definition has been altered. You still need to be a........... er .......... competent person. (Don't ask)
So, your bedroom. NOT a special location. Replace fittings, or extend an existing circuit is fine - NOT notifiable.
Having said that.............. no one knows the state of your existing circuit. Maybe it doesn't comply as it is. Perhaps adding to it will make it worse?
Electrical work is a two part procedure. First the physical alterations (perfectly normal DIY stuff.)
The second part is taking the opportunity to examine the present circuit and test it accordingly. That's the only way to complete the job satisfactorily.