Dates!! im mega confused

[Scotsgal24]

Just need to see if anyone can make sense of this for me.

My first date of last period was 13th of dec 09 and it is believed that i conceived around the 27th of december.

When i went to the EPAU for my early scans they told me that based on last period date that i would have a due date of 18th of september.

Yesterday i had my 12 week dating scan and was told that baby is measuring 12 weeks to the day and she calculated that my due date would be 30th of september.

This is my first pregnancy that has progressed to this stage so im mega confused i know that baby is measuring upto what it should be but the dating thing is confusing me.

So another question because baby is measuring 12 weeks now that is me really in second tri now isnt it?

 

[booflebump]

Go by your dating scan dates, and second tri starts at 14 weeks xxx

 

[veganmum2be]

Go by your dating scan dates, and second tri starts at 14 weeks xxx

peoples opinions on that differ.
midwifes and doctors sometimes say your in second tri at 12 weeks some say 13 some say 14.

i'm taking it as as soon as i've had my 12 week scan i'll be popping to second tri.

sorry i cant help with dates, but didn't want to read and run. xxxx

 

[booflebump]

Go by your dating scan dates, and second tri starts at 14 weeks xxx

peoples opinions on that differ.
midwifes and doctors sometimes say your in second tri at 12 weeks some say 13 some say 14.

i'm taking it as as soon as i've had my 12 week scan i'll be popping to second tri.

sorry i cant help with dates, but didn't want to read and run. xxxx

Opinions do differ, but when I did my training that was the official line we were told so thats what I go off of. Its a grey area x

 

[x-amy-x]

If you think to split the trimesters in 3 equal chunks 2nd tri would start at 13 and a half weeks

Some sites say 13 weeks some say 14. I moved over at 14 weeks, no need to make 2nd tri longer than it already is x