My boyfriend and I are thalassemia carriers need advice regarding getting pregnant?

Iam a thalassemia carrier and my boyfriend is also a thalassemia because of having a 25% chance of a thalassemia major baby we are planning to breakup.but my opinion is after getting pregnant i can do cvs and clarify whether the baby has got thalassemia major or may be a healthy that cvs will work so or not in this case.please doc give me an advice