Implant and late period

I got my implant on May 30th, and it was the last day of my period. My boyfriend and I had sex within 2 days after I got it put in and didn’t know that I had to wait 7 days for it to work. So I had to take the plan b pill. So now it’s been a month and I never got my period..is it because of the pill and the implant or might I be pregnant? Or could I be just some of the people that just don’t get their period?