Thanks for your question on Healthcare Magic.
I can understand your concern.
No, I don't think you are pregnant. But better to get done urinary
pregnancy test to rule out pregnancy.
Your all symptoms are more suggestive of stress and anxiety. Uncontrolled stress and anxiety can cause menstrual abnormality,
bloating, chest pressure, tightness,
migraine like headache etc.
So better to
consult psychiatrist and get done
counselling sessions.
Try to identify stressor in your life and start working on it's solution. You may need anxiolytic drugs too.
Counselling plays very important role along with drugs in control of symptoms.
Don't worry, you will be alright with all these.
Avoid stress and tension, be relax and calm.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.