Aw mama, totally normal yan lalo na pag early pa lang, a few of us had super faint lines din at that stage kaya don't worry too much! The HCG levels double every few days in early pregnancy, so it could just be timing or that your body's producing it a bit slower, but honestly you really should follow up with your OB para ma-check through blood tests, kasi that's the most accurate way to see kung talagang climbing ang levels mo. Maraming moms namin na nag-alala din pero lahat normal lang pati yung faint line situation, so hopefully you'll see stronger lines sa next few days!