Aw, 2042 grams at 35 weeks ay parang on the smaller side talaga based sa standard growth charts, kaya yung concern mo ay valid! Best thing to do is follow up with your OB agad para ma-monitor niya closely, a few of us moms experienced something similar and ang doctors namin nag-order ng repeat ultrasound in a couple of weeks to check if tumaas na yung weight ng baby, kaya huwag mag-alala ng sobra but do get checked talaga. Baka kailangan lang ng baby mo ng extra monitoring or maybe catch-up growth pa lang siya, pero mas safe na marinig mo directly from your doctor kung ano ang plan.