2 1/2 weeks late

I got only 1 positive test a week after my missed period, and I've been taking one test every morning and night since then to get another one (cheap wondfo one's) and they're ALL negative. Doctor said he won't do blood work until I miss my NEXT period that's due in 15 days. Im so frustrated. I understand that it could have been a chemical pregnancy, and I've gotten myself to accept that, but wouldn't aunt flow have stopped by by now? Anyone else ever have this happen?