It sounds like the last few days have been very stressful for you. The best thing for you to do right now would be to see your OB/GYN in clinic as soon as possible to discuss your symptoms and your concerns. Your doctor
can also examine you, including a pelvic exam to help determine if there are any problems. Lab testing, including a blood test for the hCG hormone produced when a woman is pregnant, can also help say with certainty whether you are pregnant or not. It will be helpful for your doctor to hear about the symptoms you state you have been having, as you could certainly be pregnant if you have been having unprotected intercourse, but depending upon your symptoms, there could definitely be other explanations for these changes in your health and it will be important for your doctor to make sure that you don't need any other kinds of evaluation.
In addition, it is likely not a good idea to check your own cervix at home. You can speak with your OB/GYN more about this, but if there is a concerning change in your health, the best thing to do is seek medical attention right away.