It was another 2 weeks later, Katara was 6 weeks pregnant, she had her first missed period, the rest of her symptoms were the same and Aang was still teaching Kya and the routine 2 weeks ago was the same.
Katara had another 7 weeks until her second trimester to tell her and Aang's friends and family, and Katara had to wait a few weeks until she could tell Aang. Katara also still has to wait 4 or 5 weeks until she and Aang could tell Bumi and Kya.
But the thing is that Katara looked back 13 years ago back when her and Aang had a miscarriage and knowing this could possibly be her and Aang's third child together, Katara had to pay close attention.