Pregnancy or not?

I had unprotected sex last week and 4 days later took a plan b. It’s now 5 days after taking the plan b and I am getting dizzy, having back and stomach cramps, being nauseous, very emotional, tired, hungry all the time and my one of my breasts and nipples has swollen, become sore and my nipple has darkened a lot. What should I do? Did the plan b not work?