Guys/gals you only need a sickness cert after 3 days .So you call sick for 3 days ,then rock up to the DR on day 4 and then get a certificate for remaining days you need.
The Dr doesn't need to know anything about your first few days off if you are worried .
This self certification for 3 days then Drs note for 4 days gives you your standard week off.
Enjoy