Gen 26:12-13 “Then Isaac sowed in that land, and reaped in the same year a hundredfold; and the Lord blessed him. 13 The man began to prosper, and continued prospering until he became very prosperous;”
The key here is obeying God when it comes down to decide what our own initiative is and what is God’s. For certain things you have to work in the same place to get the blessing from God and for certain thing you cannot do anything about it. For example in your current Job you can work hard with the fear of the Lord and God may bless you in the same Job. In other scenario, you cannot do anything for a womb to conceive. Opening of the womb for conception is done only by God. In this scenario, you have to obey how He wants to go about. If He guides you to be in faith then avoid the medical route which is similar to that of Egypt for Isaac when it was a famine in his current land. Isaac obeyed God and got his blessing abundantly from God; likewise if we obey God, He will bless us abundantly according to His plan and purpose.