Your drivers license number is actually made up from your date of birth, so won't change.
You are still licensed so continue driving, apply for a replacement right away, there will be no problem.
Plod can actually nick you if you don't have it in your possesion whilst driving, and insurance, mot, the 7 day producer is not a legal right, and the law is able to nick you on the spot as it is for everyone.
tabetha