Thank you for your question.
The best option is to see a gynaecologist who will examine you and discuss what you would like to do. They can also discuss with you the medical or surgical options should you decide you do not want to continue with the pregnancy. I would urge you to discuss ongoing contraception also so that you do not face a similar problem again in the future. If you believe you might have been exposed to sexually transmitted infection please also discuss this issue with your doctor as it will need further tests and treatment.
Please do not hesitate to see your doctor as soon as possible because they have experience of several thousand such cases. Your confidentiality will also be maintained.