HI, thanks for using healthcare magic
Pregnancy tests detect the HCG hormone. This hormone is released during pregnancy with the levels increasing as pregnancy progresses.
Normally it detectable by day 11 to 14 after conception. If the pregnancy tests were done about this time, then they are accurate. If they are done before this time, then they would need to be repeated in a few days.
A blood HCG level can pick it up earlier, so this is an option.
There are other causes for delayed period such as: (1) emotional stress or illness
(2)abnormal levels of
thyroid hormone
(3)physical illness
(4)high levels of a hormone called prolactin
(5)side effect of medication
(6)polycystic ovarian syndrome
If the test is truly negative, you may need
hormonal blood tests and imaging (such as
ultrasound) of the
uterus and tubes.
I hope this helps