Can a lawyer send a letter to someone threatening legal action If they don't help their ex wife?

Asked by M1952 (301) August 29th, 2014 from iPhone

I’m sorry if this is a stupid question, I’m just curious because my husband left me for another women and has filed divorce, I am 5 months pregnant and he will not help pay rent or anything ! Can a lawyer send a threat of legal action if he does not comply or something like that? Thank you!