The chances of you being pregnant are less, as your blood test
is negative. I do not understand that why even after Regesterone
you did not have a withdrawal bleeding.
Please consult your doctor again. It is very important to do an ultrasound
scan of your pelvis. We need to find out the cause soon. The common cause is PCOD.
There are chances of being pregnant even after taking Regesterone.
Hope I have answered your query.
All the best.