hii guys now iam in 5 th month I entered 5th month on may 8th. Previously i was called for check up on may 4 then dctr said my baby should be 18 to 19 weeks but its measurements are showing 16 weeks.my docter wrote for a tiffa scan on may 28 but by the time my baby is 18 weeks scan asked me to come after 2 weeks ie at 20 weeks is there any prblm in this can anyone ans plz