What Does An Ill-defined Mass Near The Gestational Sac Imply For Pregnancy Health?

Can I ask what means of a well-decidualized gestational sac is a fetus with good cardiac and somatic activities. There is an ill-defined mass int interior upper uterine segment with measure 4.06x3.68cm, suggestive of a focal myometrial contraction. 12 weeks and 1 day by crown to rump leng