I would not buy anymore test I would just talk to my doctor.
DH has forbidden me from buying anymore test until I am atleast 2 days late. He monitors our money VERY closely...so I don't have that much luck!!! Good Luck hun.
talk to the doctor about meds to kickstart your period.(maybe have them do a U/S first just to be sure about the pregnancy thing)
if they checked your blood i think it would be safe to say your not pregnant
I'm not sure how much tests cost where you live but here the cheapest is one for around $10. Digital is about $40 each. I used 2 a day over a six week period than got so frustrated, I went to the doctors and she did my blood! :) I would panic when my husband hid them from me and told me to wait, so I would secretly buy more!
I would definitely not buy anymore HPTs. More than likely you're not pregnant and your body just decided to take a vacation. Stress can cause things like this to happen. Also if you are extremely overweight or underweight, poor diet, increased exercise are reasons you may have missed your period.
Good luck and I hope your period shows soon so that if you're trying to conceive, you can try again! Or if you're not trying to conceive that you have some relief.