Plan B , period or implantation bleeding

I took a plan B a week ago and have had bad cramps for five days but have gotten worse in the past two days . They the same cramps I get before my period ( I get I really intense cramps) and I’ve also had all my usual PMS symptoms . Yesterday and today I’ve had spotting and there is a bit more blood today than there was yesterday ,It’s a pinkish red colour .Would this be my period starting early ? As it supposed to start in 4 days time or is it just spotting from plan B ? Or is it implantation bleeding ? I also wanted to ask if the bad cramps that I’m having could be a sign of implantation ?

I’m just confused I know plan B can mess up a cycle but I’m not too sure what the spotting is from .

( I have read the leaflet in the plan B box and I know what the side effects are I am just wanting a bit of help)