Ladies and Dr. Q PLEASE ANSWER

ends at 12 wks..some say 13..books even say different

I think I rememember hearing that the 13th week is the start of the 2ns trimester. I know there is another post somewhere on here where someone asked the exact same question :) HOpe that helps!

I went with 14th week as the start of 2nd trimester, and 28th as beginning of 3rd. Really, there's no definite answer.

Yes what everyone is saying is true. !3-14 weeks is the end of the 1st and then 27-28 weeks is the beginning of your 3rd! So confusing, why can't it just be a certain day and that's that! :)