Too bad you couldnt scan pix of your test result. Because Im not sure what youre talking about when you say:
Non-midstream, came back "borderline positive", with a faint vertical bar on the right side of the test band, and nothing on the left.
Let me ask you this: Did the CONTROL region (C) and the TEST region (T) both have lines?

If so, thats a negative. The TEST region may have a more fainter line than the CONTROL region but its still a negative.

If the CONTROL region has a line, but the TEST region has no line at all, its a positive.

If neither the CONTROL nor TEST region has no lines at all after 5 minutes, the test kit is a dud, or you didnt do the test right.

If the CONTROL region has no line, but the TEST region has a line, the test kit is a dud.

A properly working test kit must have a line in the CONTROL region.