Advice what to do

So i.been.with my man for goingbon 4 years now he has a lil boy out side our relationship before we got together im currently pregnant i didnt.wanna tell.noone cuzbi.just lost a baby in december since we been together his baby mamma has been toxica starting stuff saying im jealous of her son but in my opinion she still wants my dude he only wants to raide his son and let her be she moved on but still wont let him she always rexting my phone anout some bs its really crazy what should i do