How long for surgery? Guilty for taking time off work

Hi all,

I recently diagnosed with a lung carcinoid tumor. I am meeting with the surgeon next Tuesday and I am wondering roughly how long between meeting the surgeon and setting a date for surgery? Will it be days or weeks? I am still going in to work but it is getting a bit much for me now and I would ideally like to sign off under sick leave now but I have a feeling of guilt in case the surgery doesn’t happen for a while and it will look like I’m just skiving off if that makes sense. Would be great to hear other peoples experiences of how to deal with it, what would you do etc. 

Thank you.