welcome to healthcare magic.
there is a possibility that you could be pregnant with the symptoms you are experiencing,
i would suggest get a pregnancy
test done to rule it out.
the pills are not 100% pregnant free there is possiblity to get pregnant despite being on them.
if pregnancy test is negative then confirm with hcg
levels ,if it is still negative then you could be just experiencing symptoms due to hormone imbalance
hope to have answered your query