Ay, first time mom ka rin ba? Huwag mag-alala, yung size indication sa CAS results ay normal lang, lahat ng babies may slightly different measurements, kaya yan ay documented lang para ma-track ang growth mo. Yung "stomach bubble" (probably ang gastric bubble na nakikita sa ultrasound) ay normal din talaga, present yan sa healthy pregnancies, pero I totally get why you're worried kung hindi pa fully explained ng OB, a few of us mums din nag-panic doon before! Best thing is to ask your OB ulit sa next visit to explain it properly in detail para ma-ease your mind, or if you're really anxious, mag-request nalang ng second opinion from another OB para sa peace of mind mo. Ang importante, your baby's growing and developing, so stay positive, mama!