Has anyone started rice cereal?

Michelle • Our lil baby boy arrived 5 weeks early on 3.15.15 :) Central California
Just wondering if anyone has started rice cereal yet?  My baby is almost 5 months old and I am exclusively breastfeeding. Over the past week he has been starting to wake up every 2-3 hours at night to feed, which means I'm not getting much sleep 😥 He used to only get up twice at night but now it's more like 3-4 times! 😣 his dr wanted me to wait till 6 months to start rice cereal but I feel like he needs it now😕