Plan B

I had unprotected sex, but he didn't  cum inside me. can pre cum affect that? I took plan B two days later and then had sex that night with protection. I got something like my period for 3-4 days relatively heavy. My breasts have been tender since, and I have been slightly nauseous. We had sex maybe a week after that and used a condom. He pulled out each time and never finished inside of me. Am I pregnant? Am I close. My period should've been around now. Is it the plan B screwing up my cycle? Thank you for any help.