Pregnancy Scare

I am 16 if that matters thought I don't think it will. I used to have irregular periods but when I started having sex, I started birth control. I had normal periods on birth control for about 2 months and then I took plan be last month (March) just to make absolutely sure I was safe. They told me at the doctor that taking plan be will most likely mess with or make it so I didn't get my period for that month and it did, it was very light. And now it's one month since my last period and I'm supposed to be getting it soon (based on my birth control) I haven't gotten it yet 2 days into the sugar pills. Is there any chance that the plan B is still messing with my period? My boyfriend and I usually use withdrawal when having sex and the birth control is just extra protection on top of that. But I did let him cum inside of me twice. Once I freaked out immediately and hated that I let that happen and went to get the plan b I took back in March. A few days later I let him cum in me again but didn't take plan b that's why I'm nervous. Is it possible the plan b was still in my system and working? I'm just so worried at this point I don't know what to do. I heard that some women get their period days after they take the sugar pills. Is it possible that because I took plan b, that changed my cycle? I am so nervous please let me know any information you have. Thank you.