Even in Northern European countries the birth rates keep getting lower. And things are more or less good around those parts.
In my opinion, one of the reasons why birth rates here keep getting lower is because things are good. This may seem counter intuitive, but... yea. People living here are healthy and happy, have more or less some socioeconomic stability, rights and freedoms are well expressed and recognised, education is high and of quality.
The above results in people being more individualistic and caring more about themselves and appreciating themselves a lot more. Thus they less often end up in long lasting marriages that result in having children they get stuck with for a long time.
While this is personal thing, I know that for example, if I had remained to live back in Macedonia, society and culture would have pressured me to get married and have kids. Here in Sweden, that is not the case at all, and people respect you for your choices and who you are, rather than how you fit in their idealised society.