Luke 2:6

So it was, that while they were there, the days were completed for her to be delivered.

* 'While they were there' - It happened while they were there, in Bethlehem.
Now Mary stayed in the wrong place, Nazareth. But while they were in the right place, Bethlehem, Jesus was born. If she was in Nazareth when Jesus was born, the Bible would have been corrupted, having spoken a lie for the first time.
When Herod tried to kill Jesus, it was Africa which gave Him refuge. And when Jesus became too weak to carry His cross, it was an African which carried His cross for Him. You from Africa also need to give Him place in your heart and life, lest Africa discards you.
God in heaven planned that Jesus was to be born in Bethlehem - from before the foundation of this world.
When Joseph was warned in a dream to flee to Egypt, he obeyed instantly at night and fled.
This verse shows us that God had a plan, like a blueprint, as He also gave Moses an exact plan for the tabernacle, and charged him to be circumspect to perform it exactly as was shown him. God also has an exact blueprint for His church; do not take it likely, and be negligent with your church, children, families, etc. lest you find yourself in hell. If you neglect God's plan and do things your own way, the Bible will not become a lie, but you will be found the liar and cast out.
Mary and Joseph were not purposefully in the wrong place. But God used the godless Caesar Augustus to force them to Bethlehem. God could lead them, because they were fully surrendered to God. It is good to be wholly surrendered to God, so that whatever comes, God can still lead you in the right way.
* 'and she gave birth to her first-born son'
Woe to you, if you're the first-born and you're not wholly surrendered to God. God has declared for time and Eternity that the first-born belongs to Him. But even if you're not the first-born, you're still indebted to God to serve Him alone, for He created you and died in your place so that you could have eternal life.
Afterwards Mary bare more sons and daughters, but He was the first-born.
* 'when her days were completed ...' so too God needs to complete what He has planned in your life.
Joseph was a real man, who had self-control, as he did not touch her, until she bare her first-born son. He honoured the Christ-child.
* When they arrived in Bethlehem, there was no room for them in the inn, and they had to stay in a stable. It was very uncomfotable, but they did not complain for they had the Child with them.
* 'Jesus came to His own, but His own receceived Him not, but to as many as received Him, to them gave He power to become children of God'. He will be your comfort too, if only you receive Him as Lord and Saviour.