Hi. About 3 Weeks Ago I Had Sex. We Used

Hi. About 3 weeks ago I had sex. We used a condom and he pulled out. I am on junel fe as a form of birth control and always take it at 6 AM. However, the day after we had sex I didn't take my pill until 4PM. I had brown spotting the first two days of my sugar pills, and then heavy bleeding, and spotting again. I'm wondering if you think it is pregnancy or if I'm just worrying myself.