Well, this is an interesting way to take birth control pills. Once you stop taking the pills consecutively, your period should start within a couple days. The spotting sounds like it was trying to start, but then you took two pills. From what I remember when I was on Yaz, if I missed a pill, I could take two the following day, but if it was the second missed day I had to stop the pack and start over when my period came. If you took a pregnancy test on the day your period was supposed to start (or any day after that) and it was negative, then chances are you're not pregnant. Just to be sure, I'd do another test two days apart of each other to get a solidified "No".