Those could be pregnancy symptoms, and you may indeed be pregnant, especially if you had intercourse during your fertile time and took that pregnancy test before you were really "late." You can try testing again in another few days (once you are past your usual luteal phase length) to see if it was just too early to test or if you got a false negative result. You should have your answer one way or the other by 16-18 days past ovulation. Consult with your doctor to see what could be keeping your period away if your temperatures stay elevated for 18 days or more with no sign of your period or a positive pregnancy test.
If your period is not yet late (if you are not yet past your usual luteal phase length, or, if you do not know your luteal phase length, if it is not yet 16 days past ovulation) it is also very possible that you are not pregnant. Some early pregnancy symptoms are similar to what you would feel before getting your period since the hormone progesterone, which is present in increased amount both before your period and during pregnancy, can cause these symptoms.
When you want to be pregnant very badly, it is easy to suspect and hope that these symptoms are pregnancy-related. It is so hard to wait, but you won't know for sure until you can reliably take a test. You will have a definitive answer in a few days.
See also our Study on Pregnancy Test Timing.
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