The Gemara speaks if three keys that are not handed over by Hashem to a שליח, messenger. They are: the keys to bring rain, the keys to תחיית המתים, the resurrection of the dead, and the keys to childbirth.
These three items require prayers and are dependent completely on Hashem’s kindness.
This is the reason that Yakov responded to Rachel, התחת אלוקים אנוכי, “Am I in place of Hashem?” He would have loved to have been able to see Rachel with child, but realized that it was not within his power to do so.
Occasionally, we need reminders that very little is really within our own powers. Everything depends on Hashem and it is He that decides when to bless us with שפע, abundance. All we can do is pray and hope and do what is in our power to do. The rest is up to Him.