Negative pregnancy tests and beta test. But feel Preggers?

Rosalynn • I know I am only 19 (in April) and that my fiance is 26. But he is amazing to me and has been supporting me for so long, helping me through all the suffering and I think it`s time I give him a baby :)
Why is this happening, this month my period is 3-4 days late and I'm afraid to test today because I know it will be negative...maybe I am pregnant but just not producing hormones?