Line progression?

Clear blue is from yesterday, 13dpo & bottom is today 14dpo.

This is my first time being pregnant (also first try?!) & the thoughts of possibly miscarrying has entered my mind, same with chemical pregnancy. Wondering if it’s common to miscarry your first pregnancy, things to avoid / do to make sure it doesn’t happen… also am I passed the point for a chemical pregnancy? My first appointment isn’t until September 17th because the doctor said that’s when I can get an ultrasound.