Thanks for the query.
As you are on pill there is less possibility for pregnancy
. The nausea
could be a side effect of the pill.
But if you had intercourse before starting the pill then there is possibility for pregnancy.
So you better undergo blood test
for pregnancy which will rule out the possibility.
If test comes negative the nausea could be more possibly due to the pill.
Usually that will subside soon without any need for medication, if it persists for longer period better to go for anti-emetics and antacids which will relive the symptoms.