ok here goes:

i have just booked in for my 20 week scan, which i thought was anywhere between 18-20 weeks, anyway i have booked the date, this will be my 3rd scan, going by my first scan i will be 18w 1day, or going by my second scan i will be
19w 1day...the receptionist told me they like to see you between 19-20 weeks, so my question if i am only 18+1 when i have the scan can they still find out everything there looking for? mind you i rang another scan place and they said they like to see you between 20-22weeks???

thanks