:salam2:
Dear sister i feel you, i understand what type of situation you are in(but not fully of course), first of all i tell you that YOU MUST keep doing duas so that you may receive help from Allah(swt) and add something special in your duas: ask Allah swt to make the result of your situation be the result that will inch'Allah be best for you and the baby (and also the man you're talking about but mainly you and the baby).
Now, even if you were to ask Allah (swt) to guide that man if he doesn't WANT TO (with his own free choice) it's useless for Allah(swt) is never going to take the freedom of choice away from us for that's the mai meaning of this life of the dunya, so sister if you REALLY ARE SINCERE( and i believe you are) you have to think NOT about why the man didn't revert but rather you should think..:''Will i accept the decree of Allah as best for me coming froma loving God?Will i accept and understand that surely Alllah(swt) ants the best for me and the baby and He(swt) is THE FORGIVING ,MOST-MERCIFUL
so dear sister have faith in Allah and do your best to develop in your self the strenght to accept what is the Qadr coming fromAllah(swt)...but remember that Allah swt said:''The Dua can change the destiny..'' , so be strong i have faith in you don't you think that Allah(swt) doesn't?
dear sister
-And Allah knows best-