I was exactly the same! Took a test, saw a line, next morning, took another test and assumed it was a chemical as looked like the line was getting fainter. Gave it a few more days, and the line definitely started getting stronger. I found it really reassuring going from 1-2 weeks on an indicator to 2-3 weeks. That made me relax knowing hcg was going in the right direction.
I'm still holding off referring to midwifery until I get a 3+ weeks. I know it's not an exact science and heard that some women never even get that and have perfectly healthy pregnancies but just so cautious after loss.
I know it's hard... But wait and see. Sounds promising if it's dried the same as yesterday.