Can the word 'fertility' be used in reference to whether you choose to have children or not?

Solution 1:

According to the Oxford English Dictionary, the answer to your question is yes.

The OED (link above) distinguishes fertility from fecundity as follows:

1964 J. Gould & W. L. Kolb Dict. Social Sci. 265/2 Fertility in modern demographic usage relates to the actual frequency of births and carries no overtones of ability to have children. For the latter concept fecundity or reproductive capacity are now used.

Thus, a woman can control her fertility by a variety of means, from abstinence to contraception to abortion.

Encyclopedia.com says:

"Fertility control,” as the term is used in this article, refers to patterns of human behavior that have as their primary objective the prevention of unwanted pregnancies and births. Individuals and couples adopt these patterns in accordance with their cultural values, reinforced by formal or informal social pressures.

Solution 2:

I have never heard fertility used in that way , and it sounds kind of awkward to me. Even if it is gramatically correct, people may not understand you, or they might ask for clarification.