6 weeks 5 days test?

I feel like a first response test should be way darker than it is at 6 weeks. I’ve seen women have crazy dark ones when they’re only 4 weeks. I’m trying not to stress but my appointment isn’t for another 20 days and my previous pregnancy I miscarried. I haven’t bled at all but I know the baby could just stop growing or whatever and we would see that or an empty sac at the sono and I’m so nervous about that. Anybody gone through this and found a way to keep peace of mind? I feel so stupid but I just want this so bad.