Can’t tell if I’m sick or if this is the beginning signs of pregnancy?

Really bad nausea but no vomiting yet, cold all the time, shaky, and emotional?

I had unprotected sex on the 17th and 22nd. I took plan b both times. I’m just stressed because of college and on top of it I’m just nervous that my body became used to plan b. It’s kinda irrational. I’m also spacey and tired all the time.