Talking to an ex

Every couple of months my ex checks in on me, casual how are you doing, how’s the baby, family etc.. nothing inappropriate at all..I get comfort with this because he was an addict and that’s why we split, and seeing that message I know hes alive and didn’t overdose....however, I don’t tell my fiancé this...should I? It’s a brief 5 min convo every few months, maybe to catch up etc... I certainly don’t see anything wrong with this but could definitely use an outsiders opinion!