28 week growth scan

Had a 28 week growth scan yesterday little man is est 2lb 3 & just under bottom line 10th centile on chart got to go back in 2 weeks to see how much his gaining as got blood & protein in wee sample they are worried might slow him down with weight gain. Had same prob with 1st baby but was at 35 weeks when weight gain stopped he was 5lb 13... but then had 2 full term pregnancies now may have probs with this 1. anyone else experienced this & had healthy weight baby still 👶👣🙄