According to superstition saying "rabbit, rabbit, rabbit" out loud on the first day of the month will bring you good luck. No one really knows the origin of the tradition. The first record of it was 1909 in the publication Notes and Queries. The author's daughters would say it for luck.
Franklin D. Roosevelt has been said to have used the phrase. He also carried a rabbit's foot in his pocket. Folklore says the charm must be the left hind foot of a rabbit that's been killed in a cemetery.
Rabbits are also a symbol of fertility. With a pregnancy lasting 30 days and the ability to get pregnant again right after giving birth that's pretty self explanatory. Bringing luck to us and getting lucky themselves!
Have a great weekend!