How trusting are the early home pregnancy tests? like first response (tests 6 days sooner)?

All rely on HCG: All of the commercial pregnancy tests rely on the hormone HCG's presence and some have a greater sensitivity then others which accounts for the difference in days sooner detection.

Home Pregnancy Tests: Home pregnancy tests are very sensitive these days. If you get a positive, it is positive. If you get a negative and you think you are pregnant, repeat the test a week later if still no period.