No condom but used birth control

Just a heads up if anything is tmi in this I am so sorry. So I just had sex for the first time. It was really great, except we did not use a condom. It just happened so fast, so I didn’t think about it (I realize now I should have). I am on apri 28 day pill birth control and have been for awhile. I’m honestly not sure if he came inside me he thinks he didn’t but isn’t 100% sure. I am just so scared I will get pregnant. Someone please tell me if I should get Plan B. Thanks in advance!