moms pregnant with their 2nd 3rd ect when did you show?

I am 12 and a half weeks with my third and I feel huge. I look like I'm 5 months. I am a little chubby but not obese by any means. I have a perfectly round little belly so I know it's not all just fat if it was you'd see curves and roles. Anyway my friend is very petite and she is 21 weeks and barely has a little bump I feel embarrassed being abound her because she is 5 months and I'm only 3 and I'm bigger then she is. I feel like people look at me and think I'm pushing it out on purpose or I'm just fat. When did you all start showing? I feel pregnant already but I know baby is only the size of a lemon.