Onome

This is true, it takes up to 2 to three weeks for the medical to be processed and sent, I would suggest picking it up a day or two before your interview,  that's what my fiance is doing 

Thank you so much for the assistance Onome. You've been very helpful. 

I know for the medicals, you want it done at least 2 to three weeks a head of the interview, or you risk it not getting to the embassy in time, that's why most booked their interview with that in mind, the police clearance can be done in one day but for a hefty price I was told

Once your case says ready,  Pay the visa fee, go on the cgi website after getting your receipt,  create an online account and book your interview,  you can start filling out the DS160 at this time, it shouldn't take long at all,  our case was ready just a day later