Making a baby

I could not progress much these past months
because my wife wanted to have a baby.
That means I need to give up some energy and sperm.
Making a baby requires a lot of energy from me.
And I need to do this twice in the same week.
Note: This only happens in one month.
That means those 2 times required in the same week,
happens in only one month at a time.
I am over 40, and I cannot give up energy like I were in my 20s.
Back then I can give up energy 3 times a weekend every weekend for 6 months.