Side effects of stopping birth control

by Amylee
(Glasgow)

What are the side effects of stopping birth control pills? My period usually lasts 4 days and always has ever since I started. But I stopped taking the pill a couple of months back. Since then my boyfriend and I have had unprotected sex. This month my periods only lasted two days which has never happened before. I am really confused. Do you think I may be pregnant or have a chance of being pregnant, is it just side effects of stopping my birth control, or am I just paranoid?