Need advice

okay so I had my period 2/15-2/18 and me and my boyfriend had sex today. We used a condom the first time but he finished a lot faster than we were expecting. He only had one condom with him but we decided to keep going without one. He went and got cleaned up and then about an hour later we had unprotected sex. He pulled out and jerked off to finish so he didn't finish inside me. I was just wondering if I should get the plan B pill or since I just had my period 3 days ago and he pulled out if I should be okay. please help.