Concerning!

Hi ladies, i recently slipped up and had unprotected sex. after going to the store and taking a plan b, i experienced the worst cramps and nausea. it was gone by the second day after that i was just weak. the fifth day i was back to normal. a week and a half later i started spotting and cramping and having awful headaches and with loss of appetite and nausea. i began to look up signs of what it would be. my two options were a miscarriage or early pregnancy. i don’t want to keep stressing myself out but the cramps are the worst i’ve ever felt and i’m about 2 1/2 weeks from my period. help