Please can posters with a bit of information stop giving wrong information on areas they don't understand, it's not helpful to the op even if it's well intentioned.
Social services cannot access medical records. What they can do is ask health services if there is any relevant information that health have re safeguarding the child. Theres a huge difference between those two things.
Not all referrals result in a strategy meeting, a minority do. A smaller minority then result in a s47 (suspected child abuse) enquiry. From that, cases can go to CP conference. There is nothing about what the Op has said that suggests those processes are relevant.
There is no such thing as an initial or core assessment now, that's out of date. An assessment will generally be referred to as a child in need assessment, caf triangle assessment, or a child and family assessment or a single assessment. It just means they're finding out information and agreeing a plan. A child in need plan can be 'assessnent complete, no extra support needed, pass back to universal services'. CIN is a bit of a catch all as it covers many areas in social work, is voluntary and is not child protection. It's not something you 'escalate to' as it's no indication of threat or risk (for example, many children with disabilities have CIN assessments and plans in relation to their disability)
Op I really hope it goes well. I think some posters are being a bit harsh - it's easy to say 'nothing to hide nothing to do fear' if you've not experienced it, I hope the posters who have had some positive or sympathetic SWs has reassured you a little.