as sometimes urine pregnancy
test kits may not detect early pregnancy if you think that there is possibility of pregnancy better to go for blood test
for pregnancy once which will clarify the doubt,
if the test comes negative as you are having PMS features possibly in few days you may get periods, if you do not get even after one week consult gynecologist and go for ohysical examination and ultrasound
to find out the cause for irregular periods
then you can take tablets for withdrawal bleeding and also treatment for the cause.