I was about 25 weeks with my first before i started to show. I didn't tell my work until around that time. I remember one lady saying "so what is she like 5 weeks?" It surprised a lot of people. Lol. With my subsequent pregnancies I showed a little earlier, but not super early.
With the first it will take a while. You will have bloating to begin with. But when I was pregnant with my son I didn't show until 20 weeks or so. This is my 3rd pregnancy 2nd baby and I am only 10 weeks and I am as big as I was when I was 20 weeks with my first.