Thank you for the query.
Yes, this can be a sign of pregnancy
. However there are other conditions which should be ruled out at first.
Gas and stool blockage with abdominal pain
and nausea can be caused by partial bowels obstruction due to inflammatory bowels disease.
Upper right abdominal pain can be also caused by gallstones (especially when radiating to the back and appears after a meal), pancreas disease.
due to bad diet (low fiber intake, low water intake) can also give such symptoms.
I suggest you to visit your doctor, have physical examination, abdominal ultrasound
should be done however if you are pregnant it is contraindicated), pregnancy test, urine tests, liver tests, amylase.
Hope this will help.