Negative test with early response test 2 days before period due should i take another?

Yes: Yes. Ovulation can be several days earlier or later, and fertilization is +/- several days, repeat if menses delayed, absent.

3-4 wks after period: A blood pregnancy test can be positive as soon as 10 days after fertilization. This is usually just before your period is due or soon after. A urine test done first thing in the morning will become positive about the same time.