What Causes Cramps And Spotting When On Birth Control Pack?

So I missed a pill in my BC pack and when I noticed I had missed it I took it. The following day I took the next pill but then started spotting and having discharge even some cramping. I ve continued taking the pills, and was just curious I should continue taking them until I m done with the pack correct!? I ve never missed a pill since I ve started taking birth control 5 months ago. And from what I ve read my hormones are just messed up now and my body needs to catch up. It probably didn t help that I realized I missed it and took it 12 hrs later. I haven t had sex since then either so I should be ok in that department