Two yolks in one shell are traditionally read as doubled abundance, partnership or two things developing together. Folk belief has long linked them to twins and pairs, as a symbol rather than a sign.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.