6 week pregnancy test

Went for a urine test today, I’m supposed to be 6 weeks along. I was told my pregnancy test was faint and that the dr is estimating I’m 4-5 weeks. I’m scared I’m miscarrying because it’s absolutely impossible for me to be any less than 6 weeks. I took another test tonight at home because I’m wondering if I just accidentally drank too much water before I gave them my urine sample. I wasn’t even thinking about it and drank like 3 bottles before I went to my appointment. What do you ladies think? Is the line an acceptable amount of dark for a healthy pregnancy at 6 weeks?