Hey mama, 110 grams sounds totally normal for 15 weeks, baby is still super tiny at that stage kaya that weight is right on track! I'd double-check with your OB though to be sure, pero from what a few of us moms experienced, the ultrasound measurements can vary a bit depending on kung gaano ka-accurate ang dating ng pregnancy, so best peace of mind is to just ask your doctor directly. Congrats on your pregnancy!