NEW TO ALL THIS

Hey ladies, I'm knew to all of this, I saw my fertility doc today and he is suggesting starting Clomid next cycle which is exciting yes, but he said Clomid on cycle day 4 through 8 then come back for a shot then they will give me a calender on which days to have sex, this is gonna sound stupid but I'm not understanding what exactly this treatment is because I thought you take clomid on certain days to help ovulation and thats it, so why am I doing a shot and whats the purpose?? I know shoulda asked but it just went to fast and now I have 100 questions