What's more sensitive ?

I took an E.P.T test yesterday , positive, another today , positive, about the same darkness, another maybe 1 hour later because I couldn't wait. Positive but significantly lighter, understandable since I didn't give hcg time to build up . Then I took a frer about 2 hours later , and negative. (Yes I have a testing problem lol) my question is. Can I trust the e.p.t tests even though the frer was the only negative I got ? Is frer not as sensitive as the other brand ?