Pregnancy or slow period

Aria

So i had sex 3 days before my period... and I my period was late I took a plan b though and I don’t know if it’s because of that ? My period was due the 10th. I am now 8 days late but yesterday I started having dark brown blood but a little bit and today it’s light but a little bit hardly anything. I’ve been cramping for two weeks so is this my period coming due to plan b just late or can I’ve pregnant ?thanks I’m advance