MY PERIOD IS LATE

Maria

I am on the pill, and My last period was dec 15-18 and my boyfriend and I had sex and he came inside me that same week or week after that (don’t really remember). I took a plan b the next day, to just be safe and because these last few weeks I haven’t been taking my birth control as I should like missing a day or 2 and doubling up. My period was suppose to come on the 16th of January but it hasn’t, it is 13 days late I took 2 test both negative. I have always had irregular periods and I got on birth control to regulate and it did, until this. Could it be that me not taking my birth control like I should plus the plan b mess up my period?

PLEASE LET ME KNOW IM SCARED