Easy at home vs. First response

So I've been using 'easy at home' OPKs the last 4-5 cycles to track ovulation and I've had no issues with them. Everything its super obvious when I peak and ovulate and I get my period every month exactly 14 days past ovulation except in april when I had a chemical pregnancy...so this month I questioned an elevated level on CD8 which I knew was WAY too early to ovulate so I went out and bought the expensive first response ones to "double check" which validated I was not. So now I'm at CD 15 and have the positive on easy at home (around same time each month) but not on first response...just more curious than anything if anyone else has used these two and had thoughts??