I agree. Only your Dr. can really tell you what is happening. Good luck to you.
If you took 2 tests that were done according to the directions and they were negative, your chances of being pregnanct at this point are very slim. Having a late or missed period in and of itself does not automatically mean pregnancy. You may have for whatever reason had an annovulatory cycle and therefore your body is not ready to complete your cycle. If you feel something else is going on, schedule an appt with your gyn to discuss it.