Hallow Dear, Missing a period is the first cardinal symptom of pregnancy. You have not mentioned about missing your period. All other symptoms of early pregnancy appear about a week after the missed period. If you have not missed your period, the symptoms you have mentioned cannot be pertaining to the pregnancy. Moreover you are on Cerazette contraceptive pill. So the chances of pregnancy are still rare. You are well protected from pregnancy. Cerazette is a Progesterone only contraceptive pill containing desogestrel. Progesterone does cause irritation of the stomach resulting in nausea, pain in stomach, etc.. To get rid of these symptoms, take some proton pump inhibitor antacid like Pantoprazole daily. Progesterone also causes engorgement of breasts with tenderness. Salt restriction may give some relief from this. Use appropriate size supporting brassieres. Since your pregnancy test is negative you may exclude the possibility of pregnancy. However, if you have missed period, you may repeat the test again on overnight first morning urine sample after a week as theses tests done too early may report false negative results. I hope this helps you. Dr. Nishikant Shrotri