Evap line on first response?

First time IUI here! Had the trigger shot (Ovidrel 5,000) on 7/12 and IUI transfer on 7/14. I have been using the easy at home strips from Amazon to track when the trigger shot would leave my system. They looked completely negative a few days ago but the hcg sensitivity is 25 miu/ml. I took a first response yesterday morning and this morning. The hcg sensitivity is much lower, but I can’t tell if they’re positive or evap lines?? I read them both within the recommended time frame and I have never gotten a line on these ever before!