Conception calculation

[Handy83]

Just wanted to know if anyone knows how midwives calculate the number of weeks before your booking appointment. The first day of my last period was 27/09/17. This was 7 weeks ago yet the midwife says I'm 9 weeks. Is this correct

Wait so you haven't had a scan or anything yet? Then you are correct, you count from the first day of your last period, so 7 weeks. Maybe the midwife miscounted?

No not had a scan yet. Bit of a mix up cos the midwife on the phone told me 3pm but wrote down 1pm so missed the appointment. Got another appointment for Sunday. She used some form of date wheel so that's why I asked.

You’re right, it’s 7. Prob just human error.

7+3 to be exact.

I thought so. Thanks for the responses. Bit anxious about the appointment but should be ok. At least my partner can be there to answer his family questions