Hi. I Had Unprotected Sex A Few Days After My

Hi. I had unprotected sex a few days after my last period. I've been getting a lot of cramps and I am super exhausted after about three hours of school but I have been getting plenty of rest. I lose my appetite and I threw up a few days ago. My breasts feel super sensitive and my period came a week and a half early. My period is usually very heavy but it's lighter than usual, and it completely stops at night. Am I just imagining things or can I possibly be pregnant?