Nervous and I really need some input to maybe put my mind at ease. PLEASE READ:

I am on birth control but had not been taking the pill at the exact same times everyday, although I never missed a pill. 17 days ago I had sex and the condom broke so I got nervous and took a plan B approximately 13 hours after. The day I took plan B I was supposed to start my placebos in the birth control pack but instead I skipped them and went straight to a new pack of active pills. It has been 16 days since i’ve taken plan b and i’ve had no spotting or bleeding. I’ve had sore breasts and cramps as well as headaches here and there. I’m supposed to start my period this Sunday. Do you ladies think the Plan B was even necessary to take? Why do you think I haven’t spotted or anything yet? I’m really stressed.