Ojalá - distinguishing between future hope/past wish

Hello, I've been confused how to combine ojalá + [verb/event] to distinguish between a hope for the future and a regret/wish about the past. 
A quiz example of each:  
--Ojalá yo ________ un hijo a los 33 años.I hope I have a son by the time I'm 33.(HINT: Conjugate "tener" in El Imperfecto de Subjuntivo)
--Ojalá ________ mejor nuestra propuesta de trabajo.I wish you considered our work proposal more closely.(HINT: Use the "tú" form to conjugate "considerar" in El Imperfecto de Subjuntivo)
It seems like these both use ojalá  + imperfect subjunctive, but that one is a hope for the future and one is a wish/regret about the past. I might be missing something.
How could we distinguish between, for example: 
"I hope I have a son by age 33 [and I still might]"   vs. 
"I wish I had a son by age 33 [but I didn't]" 

or 
"I hope you consider our proposal more closely"    vs.  
"I wish you considered our proposal more closely [but you didn't]" 

Thank you!