It is common for girls who are following Kayla's BBG program to see some initial changes around the 3-4 week mark.
However, this will differ from person to person depending on your nutrition and other lifestyle factors, such as stress and how much sleep you are getting etc.
Also keep in mind everyone’s bodies are different.
What may take someone else 3-4 weeks, may take another 10-12 weeks.
When tracking your results, it is also important to take regular progress photos (i.e. once a week or once a fortnight).
Whilst Kayla also recommends tracking your weight, you should focus your attention not only on the changes in your photos but how you FEEL overall! This is because some changes may not be visible on the scales, but very visible in the mirror and in the way you feel!