Aww, that's a cute little bump. You look so innocent! I hope that doesn't offend you tho, I mean it in a nice way!
My bump just appeared one day like you said, and then it stayed the same until I was like 8+ months. I could easily hide my prengnancy if I wanted to up until that point. My mom got me a ton of maternity clothes that I barely wore. Tho now after having the baby they are comfy to wear cuz they are nice and loose.
Congratulations on your pregnancy by the way, and also for being so mature about it all, your a strong woman!