Still hopeful

Well today is day 4 with a missed period according to my log calendar. I tested yesterday again !! and it was negative ☹. Can it still be too early for a hcg pregnancy test to show positive? What's the difference between a normal first response and those small cheap 88 cent hcg preg tests? Should I maybe just wait another week to take another test ?! I'm so hopeful but it's making me so anxious to know being that I've missed four days already...also I have been using hcg pregnancy test only . Is maybe my hcg not high enough ? Do I need to take a regular pregnancy test ? Help here ? Lol