Line staying faint

Mo

I’ve gone from overjoyed to over worried! I’m 42 1/2 and got my first bfp on Friday night. At that time I was one day late for my period. It was the evening, and so I didn’t think much of it when the line was mildly faint. I mean...it was obvious...no line eyes, but not as dark as the control line. I’ve since taken two more tests, and they’ve also both been positive. I’m now 3 days late. But the line isn’t getting any darker. At my age, I’m terrified that it’s a chemical, or just will be a miscarriage. Anyone else been through this? Any advice? Here are my first 2 tests for darkness reference!