I had unprotected sex 3 weeks ago(march21st) about 3 days after my period ended and I took plan b ( it was the second time I took plan b the first time was a month ago) the next day March 22nd. Ever since then I’ve been having stomach cramps that come and go to this day. I’ve also been feeling back pain and my chest feels tight. My period is supposed to come in 5 days. I took a pregnancy test and it came out negative. Could I be pregnant? Or why am I having these cramps and a nauseous feeling