Thanks for the query.
Menstrual irregularity can occur due to many causes like hormonal
imbalance, stress and strain, weight changes etc.
So the hypomenorrhea
you could be due to one of these.
And just by symptoms we cannot confirm or rule out pregnancy
But as sometimes urine pregnancy test kit may not detect early pregnancy, you can go for blood test
for pregnancy once to get accurate result. Meanwhile you can take symptomatic treatment.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429