I'm having mine this week, so just under four weeks before the interview. We're planning on going away at Easter for a holiday and didn't want to rush anything. Otherwise, I would have allowed three weeks (2 weeks plus contingency in case anything goes wrong)
I think the advice from the consulate is that you can have your medical around the time of interview but, if the consulate doesn't have the medical results at the time of interview, they won't finalise your case. They will just pend final approval of the visa contingent upon receipt of the medicals. IMO.
Having said that, I'm pretty sure
@GANDT-SYD had his medicals a week before the interview, so perhaps ask him how he did it? If you can get it all done in the space of a week, medicals and interviews, that might work?