A couple of things come to mind.
1. You seem to be on a 31 day cycle. In most cases with a 28 day cycle you'd ovulate between days 11-16. You don't say how long your period runs but waiting 14 days to start tracking ovulation may be a bit late. You indicate you ovulate on day 21.
2. Your pregnancy tests were negative. It does not matter what happens after the time expires.
3. Testing early with HPT's is not reliable. They are likely to read "negative" when testing before your period is due.
You say your period is starting now, the 10th? If so, and it is a "normal" period then it is unlikely you are pregnant.
Don't get frustrated. You will get pregnant. As Bree says "don't stress."
Track your ovulation for another cycle. You can use another method as well, maybe the basal body temperature.
Hope it helps.