I think you are muddling the SSP (State) system and your employer's system.
With SSP, you can certify yourself as sick for up to the first few days - then after that the State requires that you produce a doctor's certificate. The process is managed through your employer who pays you the necessary amounts of SSP but you never get paid for the first 4 days - the Waiting Days that you refer to. SSP is paid at the rate of about �75 per week.
If your employer has its own sick pay scheme this works according to its own rules.
You are typically paid in full for all the days you are off, but there is an annual limit - sounds like 10 days max for your scheme but ask your employer. The employer then reclaims some of the full pay you have been given from the state.