It bothered me too; it didn't change till 15 wks; just a few days ago. I don't know why.
Hi hun, I think from memory it didn't change on Ruby's tracker till I hit 15 weeks which is stupid. Most places I read say 2nd trimester is 14 weeks.
I know that, I was just wondering when the tracker on my profile changed :)
You're actually in your second at 13 weeks. 4 weeks in a month and a normal time to have a baby is 37 to 40 weeks.