The FSRH has released new guidelines (as of Nov 2020) regarding contraception. Please read them HERE
Contraception services are free and confidential, including for people under the age of 16.
If you're under 16 and want contraception, the doctor, nurse or pharmacist will not tell your parents (or carer) as long as they believe you fully understand the information you're given and the decisions you're making.
Doctors and nurses work under strict guidelines when dealing with people under 16. They'll encourage you to consider telling your parents, but they will not make you.
The only time a professional might want to tell someone else is if they believe you're at risk of harm, such as abuse. The risk would need to be serious, and they would usually discuss this with you first.