PREGNANCY SCARE

My boyfriend & I have been having unprotected sex for 6 months & I have always gotten lucky & never became pregnant.. Well, last month he decided to cum while he was halfway inside me.. The same day we did it, I also went & got a plan B pill & took it that day just in case. We remained calm until 4 days before the day my period was supposed to start, & then I freaked.. We went & got a pregnancy test & it was negative.. But we were both still anxious for me to start. I was supposed to start today & I didn't... We are extremely nervous now.. Please help.