Could I be pregnant?

Took plan b on February 4 and got my period on February 12-17. Got drunk one night with my hubby and we had unprotected sex and he came in me crazy thing is I was my fertile day also 🙈🙈🙈 now I'm 9 days late. Don't feel pregnant but beside I was home all day then got tired after watching a movie and knocked out for almost 2 hours. Took 3 test and all negative?? What is going on? You think the plan b messed up my period for this long or should I do a blood test?