If you wish to access the local sexual health or family planning clinics then you are able to self refer without seeing a GP. Most local services offer drop in clinics as well as pre-bookable appointments. They also commonly offer designated under 25's clinics. You are able to ring and book an appointment using the contact numbers below or can simply drop in to the appropriate clinic.
https://www.seftonsexualhealth.co.uk/clinic-times-locations/
https://www.cashlancashirecare.nhs.uk/clinics.php
https://spectrumhealth.org.uk/services/sexual-health/find-clinic/wigan-leigh-sexual-health-clinics-3/