Freaking a little

Jodi
So last month I had my mirena removed, I got my period like a day after. I was told I should go back to my regular period. But my boyfriend and I don't use pertection and he says he cums inside me every time. Which I don't mind. It's almost the end of the month haven't gotten my period yet. I was supposed to start two days ago. Took a pregnancy test last week and it was negative. Any insight?