Help

Patient: Hi, im wondering if you can solve something for me please?!i had my first scan today confirming i am 16 weeks pregnant, i am confused by this as i was on the pill so do not know when my last period actually was but i missed taking the pill on the 19th October, and again on the 15th November! I took a pregnancy test on the 21st of November and it said i wasn’t pregnant, so i must had got pregnant on the 15th nov right?! So why would my scan say im 16 weeks when i should had been 15 weeks?! IM so confused right now!!

Doctor: