This is a good question. I'm assuming that by morning sickness you are referring to nausea and vomiting
that occurs mainly in the morning. It is very important that you make an appointment with your primary care doctor
to discuss your symptoms and have a full history and physical. Depending on what your doctor discovers during your exam, he or she may order blood work or a urine sample. When most people hear the words "morning sickness" they immediately associate them with pregnancy. Although you noted that your periods are regular, your doctor will still likely do a pregnancy test if you are sexually active. Sometimes you can have bleeding during pregnancy that is mistakenly thought to be a normal period. Stress can also often manifest as gastrointestinal complaints. Your doctor will likely ask you many questions about your mood, appetite, libido, sleep, and feelings of guilt. It is also possible that you are suffering from IBD, or irritable bowel disorder. This is characterized by a combination of bloating, nausea, constipation, and diarrhea. It is often associated with anxiety and/or depression
. Again, it is very important to make an appointment with your doctor to get a correct diagnosis and appropriate treatment.