Pregnancy of 29weeks. Is all r fine?

My wife is pregnant of 29weeks 2days as on 24.01.18. She done growth scan on 24.01.18, the results shows BPD 7.8cm (31w2d), HC 28.2 (30w6d), FL 5.55cm (29w2d), AC 25.7cm (30w) and all other parameters and positions are perfect. Her 21 weeks 1day scan (anomaly scan) report shows only 1-2 days advance growth, but this report shows 1-2 weeks advance growth. Pz doctors tell me it's normal? Is that means our baby will have little big head? Why 1-2 weeks advance growth showing? Is it for diet? Is all r fine?       She is taking thyroxine 50mg (Thyroid is under control for 1.5years), GEMCAL D3, MCB, Metformin 500 for PCOd and LIVOGEN as last time hemoglobin report shows 10.2). We have done some test as per doctor's advice like serology etc.. and last 15 days ago done PP and fasting sugar test which is also normal. But GTT not done.