Finished 21 day pack and no sign of period i also took two doses of plan b on second day of bc.didn't miss any pill after. should i start another pack?

Do a preg test: If it is negative start your next pack. At times can go with having a period on the bcp

Check first: I recommend checking a pregnancy test first, if negative, there are other things that can cause the period to not start. Your doctor can help to figure out what else may be causing, if you are not pregnant., .

Preg. Test first: That would be ok but first check a pregnancy test.