Dreams are mostly a reflection of what is going on in our life presently or past events. Somewhat unhelpfully the subconscious can employ very abstract metaphors to explore the issues at hand. As Sephirah says, that imagery can mean different things to different people depending on the circumstances and I would agree that the island dream would seem to indicate a sense of isolation but with a means to communicate still available..."if you want to get off the island reach out". The birth dream may be a latent desire to do the same but usually dreams represent ourselves - birth is the very symbol of new life, and as you say you've had a big change in your life and maybe a new you desires to emerge into the world - essentially you are giving birth to yourself. What that ultimately means is how you feel during the dream - pain, afraid, joyous, frustrated, etc. As for the ex crush dream, what did she mean to you, what did you envisage your future together could have been, why did it never eventuate and what did you feel about that? The fact she is in your dreams usually means that your subconscious is either trying to heal your emotions around that or something has triggered it (a similar circumstance, maybe you someone who looked like her, a blast from the bast, etc) and your subconscious sees parallels.
The fact that you have a trinity of dreams that are recurring in a similar time frame would indicate they are interconnected somehow. Resolving the deeper meaning may require breaking each dream down into your feelings about them and see how it applies to your life at the moment.
Of course, as Sigmund Freud once said of dreams and symbolism "sometimes a cigar is just a cigar".
