Need Opinions - Line Eyes

I need some advice!

I got a very faint line (VFL) on 12 DPO, so I waited and took a digital test on 13 DPO, which came back positive. I tested again the next day, and it was positive as well. Since then, I’ve been using easy @ home strips because I had them on hand. While the tests show positive, the lines aren’t getting darker, and I read online that this could mean the pregnancy isn’t viable.

Today, at 18 DPO, I took another digital test, and it was positive—making that four positive digital tests. However, the faint lines on the easy @ home tests are making me nervous. Should I call and request a blood test, or wait for my confirmation appointment on 12/19?

This is my first pregnancy, and I’m experiencing mild cramping, sore breasts, and fatigue, but no bleeding or other symptoms. I’d appreciate any advice to help me feel more prepared.ty