Telling Ex About Pregnancy with Current Husband?

Natalia

Do I need to tell my ex I'm pregnant? We have a son together who is almost four and we've been divorced three years. I'm now remarried which he's aware of and I told him personally when I got married (we eloped). He has our son every other weekend and we really don't speak much. His sister follows me on instagram so if I don't tell him personally he'll most likely find out from our son or his sister. Thoughts?