I got a B in AP Calc

So math has never been my strongest class but I’ve always clinched an A or A- and have stayed in the honors track. I’m going into Government so the ability to differentiate will likely not come up in a job requirement but I’m very concerned that Dartmouth will see it and think I’ve gotten lazy. I had talked with my counselor about my struggle and she said something in her letter about it, but idk if that’s enough.
Given I had an okay shot of getting in before, does this screw me over?

One B will not keep you out of any college.

I am well aware of that, I’m just concerned it’s a red flag for Dartmouth

It’s not.

Dartmouth, and many of its peers, routinely reject applicants with 4.0/36/1600 stats while accepting some with less-than-perfect stats. One by is hardly a “red flag.” You may not get in, but if you don’t, I highly doubt that it was as a result of a B. Good luck.

I’m sure the counselor handled in appropriately – as in, not saying anything. Absent a serious medical/family issue, ‘explaining’ a B is itself a red flag – no one like grade grubbers.