If your ultrasound was that early, there is no way the doctors would confuse the age of the babies.
I got, y date by ultrasound on oct 16 and i was 6 weeks and like 4 days thank you so much i figured doctors would be able to tell if i was farther along
How did you get your due date, from an ultrasound? If so, when was it, and how far along did they say you were at the time?
Conception calculator gives the following just from that due date (it will be as accurate as the due date was):
Probable date of ovulation: September 11, 2012
Possible dates of conception: September 7 to September 15, 2012
Due date: June 2, 2013 (40 weeks)
I assume he will insist on a DNA test, but the timing shows it's all him with no possible question. Not only do the numbers not go back as far as the 17th of August, but you had a period after that.