Mother in law issues...

Me and my fiancé have been together for a year and a few days (April 16 made a year) anyway his mother has NEVER liked me because I am helping him get a job and help him make positive changes in his life his WHOLE family is jealous of me they all admitted it!!.. We are currently TTC baby #1 we decided to start really trying since we are engaged but we have been arguing lately about his mom not having anything to do with our child once she/he is born.. His mother is a complete ass hole to me and he knows it he confronted her about it and she started that bullshit crying saying she likes me etc so his sister and her girlfriend got involved and cursed me out etc and we don't like each other his WHOLE family is jealous of me I tols him I DONT want my kids having a relationship with them once we concieve but he thinks I'm not being fair... Am I the one in the wrong?