I'm 27 weeks and my doctor said the best time to do the 3D/4D is at 30 weeks + $125 fee. 
 We are still deciding because we also have 1 last songram at 35/36 weeks of pregnancy to measure & see how he is doing + it's free. What are your opinions? Should we just wait since it's an extra month wait??? Or do you think it will be a big difference in his appearance between the two...