Period??

I have a small concern , I had unprotected sex and missed a pill so I went on Ella . According to the pamphlet Ella and birth control should not be used together because it can counteract with each other so I stopped taking birth control the next after using Ella. I had a withdrawal bleeding , which seemed like a period because I wore pads and all for 3-4 days. Could there still be a chance I’m pregnant or was this just bleeding from stopping the pill

He didn’t cum inside me at all . Any thoughts... I took a test today (2 weeks after sex) and it was negative , should I still be worried