Did the plan b work ? 🧐

Okay my cycle is usually late so i would say its between 29-35 days. My period ended on 09/15 and we had sex last week on 09/19 and he came inside me so i took a plan b 48hrs after which would be 09/21 but then we has sex on 09/27 and when he came inside me AGAIN i started to bleed heavily the next day ( as if i was on my period) and so far it has been 2 days where i have been really heavy and 2 days were it is still spotting but its not as heavy so would i consider this as spotting or should i be worried? what do you guys think??