Hello, I would be happy to help you today.
If we assume that ovulation occurred on about cycle day #14, AND that you concieved, then a pregnancy
test should be positive at this time. Given that the tests are negative, it sounds like you are NOT pregnant. It is likely that your symptoms are related to your cycle. It can be confusing when you are "late" and with negative tests, but here is what I would recommend:
1. Repeat the test in one week, regardless of your cycle
2. If you don't get your period in one week, it is likely because you had delayed ovulation or did not actually ovulate. In this case, you might need medication to start a period, such as progesterone
3. If things remain confusing, your doctor could check a blood pregnancy test and/or a progesterone level to see if that clarifies what is going on.
I hope this helps. Good luck!