Hi there, I have understood your concern. I will suggest you the best possible treatment options.
1 ) First of all do not panic.
2 ) As per your history, you have irregular cycles and unprotected sex act in the previous cycle, and from your symptoms you feel as if you are pregnant.
3 ) If you have crossed your dates or it is 15 to 20 days after the last unprotected sex act, then I will suggest you to get morning's first sample of urine tested for
pregnancy. In case of doubt blood
beta HCG test and USG will be of help.
3 ) In case you are not pregnant then you can simply wait for the onset of periods. Then for your symptoms you can take anti emetics and antacids, your treating doctor will help you about the prescription for the same.
4 ) If you are pregnant, then you can continue with the pregnancy if you wish so, or else you can opt for termination of the pregnancy with medicines safely till 9 weeks of pregnancy under medical supervision.
I hope this answer helps you .
Thanks.
Dr. Purushottam Neurgaonkar