First Response Preganancy Test?

I didn't get my period for 5 days now. I have never been delayed since. I tried first response pregnancy test to check if i'm positive. Unfortunately, it's negative. But I was wondering if i did the test properly. Do we need to fill up the cup provided with urine or a small urine sample will do? I only have a small sample of urine in the cup. What I did is I just tip the cup so that the urine will touch the maximum level line provided in the strip. Do I need to retest? And hopefully get a positive result?