Clomid questions!

Hello ladies! I start taking clomid in a few days and I forgot to ask the dr some questions - he was talking so fast and it was really overwhelming!
Question 1 - can you take clomid with vitex, maca root, or any other supplements? I mainly need to take something to increase cm.
Question 2 - my dr didn't even mention he chance of multiples with taking clomid, I just have read about it on here. What are the chances? I tried googling but couldn't find an answer!
Thanks ladies :) good luck to everyone!