On one hand, how is 15 weeks measured? From the onset of the prior menstrual period? How do they know when that occurred or when I had sex?
Suppose the doctors think I’m 18 weeks pregnant, but I insist it’s no more than 12 weeks and I have a receipt for tampons that I purchased 11 weeks ago.
(What they don’t know is that I bought the tampons in anticipation of a menstrual period that never occurred. I kept the receipt just for this occasion)