I was told these u.s pictures of my twins were taken appx 15 days after conception. (4weeks preg?) question: is it possible and what is seen in photo

No. Try CONCIERGE.: No pictures are viewed on this free forum. If wanting a personal consultation, try HealthTap CONCIERGE, our premium forum for specialist virtual consulations (ask for an Ob-Gyn doctor). That said, 15 days is too soon to see an embryo on ultrasound. A transvaginal ultrasound may see a sac at 15-20 days post-conception. See some examples are at: http://www.ultrasoundpaedia.com/normal-1sttrimester/