He also pulled out, forgot to mention.
Missing pills at the end of your pack shouldn't lead to becoming pregnant. If you missed them nearer the start or middle - then it would be something to be concerned about because it could lead to you ovulating because of missing those pills, but by the end of your pack you've most likely missed that window so you should be fine.
Just note that pulling out isn't effective and can still lead to pregnancy, but if you took all the rest of your pack as instructed then you should be okay.
Thanks for your comment. I've started full-on withdrawal bleed now. But what do you think about taking Plan B. just in case?
I'm quite worried now, as my withdrawal bleed hasn't actually started. There was some brown spotting, occasionally bright pink, but not very much at all. I'm currently in a country where medical advice concerning pregnancy is very odd and not reliable.