Thanks ladies. I've got heaps of sick leave up my sleeve.... months of it actually so it's not an issue if I need it.

My boss just needs to know how long roughly I'll be off for so that our team can plan around it. If it's mid week I will probably tell him I'll take 3 days off (including the op day) and then play it by ear. Then again if I get given a certificate for a week I will be happy to take it.