I got a first response early pregnancy test. It was negative. My period is about 2 weeks late, I am on progestin only birth control (this kind does not control your period) and haven't had a regular period since, but I have never missed one. I have been on it about 7 months now. I had super light spotting last Thursday and Friday but no period ever came. They say that the pregnancy tests will be effective 4-5 days after implantation bleeding which it's been that. I got a negative today(tues) I just don't know whether to completely trust it. What would you do?