I am 19 days late today always dizzy headaches cramps lower back pain nausea sometimes I have taken 2 HPT's 1 April 25th came back negative then this morning another neg?

When I was pregnant with my first child I was almost a month late before I got a positive test result. I tested every week from the first day of my missed period and kept getting negative results. FINALLY in week four of my missing period it was positive! So it can happen, but I suggest you go see your doctor for a blood test to find out for sure.