Rainbow baby advice!!

Hey everyone,

After having 2 miscarriages I’m hoping this is my rainbow baby. I can’t help but be paranoid and I guess it’s normal however, I am 15 weeks and 5 days and I don’t feel like I’m showing and I can’t help but think bub isn’t growing.

I’m quite petite so I think it’s odd I’m not showing, I have a Doppler so I can still hear bubs heart beating away, is there any chance something could be wrong or am I just over thinking?