Depends on the girl and the number of babies you’ve had. If you’re on your 4th baby people will be able to tell sooner than your first.

Generally it’s unnoticeable for everyone in the first trimester. Second trimester is probably pretty safe too, this is when you might start looking a little fat by the end, but not really pregnant. Third trimester is when the majority of the weight is gained, and the baby grows the fastest. In the last month of the third trimester the baby gains like a pound per week.