I used a cheap early response test 4 days before my af was due and I got faint bfp. I waited until AF was late and went to GP surgery with an early morning wee sample, but they would not confirm it with sample I gave them as they said it was taking too long for the positive line to appear. I had no pg symptoms, so obviously it was just taking a while for the hcg levels to rise. I took another sample to GP 2 days later and this time they said it was definitely positive.
It definitely messes with your head when nothing will confirm things for you. Hope you get a definite answer soon. Your hormone levels may just be slow like mine were.