Can drinking too much water determine the results of the pregnancy test?

Not really: Drinking "too much" water, and i'm not really even sure what that means, could only potentially cause the pregnancy test to be negative if it is actually positive as there won't be enough HCG to trigger a positive result. The first urine of the day is usually the best time to do a pregnancy test as it is typically when a person's urine is the most concentrated. Good luck!

Not very much : Home pregnancy tests are very accurate. They are the same tests used in a doctors office. They can detect a pregnancy 7-10 days after conception. The best time to take one is when you miss your period. If you doubt the result you can repeat it in 1-2 days. If you were pregnant the hormone level would rise enough for detection.