Bump question

BabyC2012

Please forgive me if I sound like an idiot with this post! At 17.5 weeks I don't have a bump but I do have one chubby stomach. I can feel the baby pushing out slightly in my lower pelvis and I assume once the baby moves up and pops out then this becomes my bump? I have gained about 7 pounds so far and it is all in my tummy and boobs. Here is my stupid question---what happens to the belly chub when the bump pops? Does it stretch over the top? Is there a layer of it over the bump? Truly I feel ridiculous asking but I am seeing pictures of everyone else's adorable bumps and I am just not sure anatomically how it will happen to me with my current shape. I haven't bought any maternity clothes yet because I feel so clueless about how the changes will take place.   I have a sporty body type with average weight and probably above average bone/muscle density.  I am also only 5'2.  Thanks to anyone who has a response (and is able to get through my confusing paragraph....)