First response test question

So my friend gave me a first response pregnancy test that she had. My period is late and I took it this morning. I did the cup not the stream. I put the absorbent tip in the cup for five seconds. And it came negative. I went online and it said I had to put the absorbent tip for 20 seconds if I wasn't doing the stream. So now I'm thinking if it does make a difference since I putted it for 5 seconds since that's what I thought. Now I'm thinking if I should buy another one.