Plan b/loosing virginity

Hey girlies, Ik this was an irresponsible choice for my SO and I, but I lost my virginity on thanskgiving (thurs) he pulled out, but for peace of mind I took plan b. We went on a cabin trip and had sex again Friday, but he didn't even cum, but then last night we had sex again and he came inside of me. The plan b says not to take as regular birth control, but is it ok to take it again this afternoon when we get home from our trip? It'd be the only time I took it again. Also since I took plan b Thursday evening would it still have effect for last night at all? I'm also not ovulating as far as I know. I'm suposed to start my period in 4-5 days. I know it was a poor decision, but you can't undo what's already done, all I can do is make sure I take care of it and that it doesn't happen again. Any advice appreciated:)