Feeling very insecure

so I'm 21+3 weeks and I'm only 17. I'm going to school and keeping my pregnancy a secret. Which is easy because I'm overweight and wearing baggy shirts. But with my growing womb, I just feel like Ive gained tons of weight and no bump.

do you guys know how I can gain confidence? cause right now I have none and it's really bringing me down.. UPDATE: I forgot to mention that I'm going to be having a open adoption with him, since I don't have the money to take care of him but I want him in my life.