Sudden stopping of the pills can cause withdrawal bleeding and even breakthrough bleeding or spotting. To postpone the bleeding, you can start with another pack of birth control pills without taking any break in between. You can also postpone your periods by taking norethisterone which is often used to postpone a period. The dose is 5mg three times a day starting 3-4 days before a period is due. It can be continued for up to 2 weeks or so until you want to have a period.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.