Forshelby-I dont get how your baby is the size of a banana i had Abbi at 19 weeks 5 days and she was the size of a 17 weeker because of her skeletal dysplasia and she was still a decent size she was 18cm long and her little head was the size of a tennis ball maybe the banana refers to the weight i know they weight about 200-300 grams about 19-20 weeks but she was most definately bigger then a banana.