A: I've taken one dollar ones and they at one point have been more accurate then the 13 dollar ones save your money and go to your gyno, if you are missing your period at least then you'll save a trip and know why.
A: I bled a few days after, it's completely normal that I know of but keep a look out for future symptoms like polysistic ovarian cancer(cysts on your ovaries) which I have now.