Hi, I'm 16 Years Old. I Just Had Sex With

Hi, I'm 16 years old. I just had sex with my boyfriend and we didn't use a condom. I am on the pill but I struggle with taking it on time. I do take it everyday though. I'm not sure if he came in me because he tried to pull out but we aren't sure if he did in time. I started my period April 1st and have been off of it since Tuesday. I was wondering what the likelihood is that I am pregnant or if I should go get a test or take Plan B. Thanks so much