Four tests over 4 days. Lines are faint and not getting darker..

I’m about 19 dpo.. and my test lines are still so faint I can barely see them. I took a digital test and it was positive. Took it apart and the lines were both dark. But these first signal tests are still barely visible. I’ve had 2 mc’s within 2 years and I really want to be excited about a positive test but I’m so scared I’ll just be disappointed again.