Hello, I'm 21 Years Old And I've Been On Birth

Hello, I'm 21 years old and I've been on birth control for a few years now. I never take it on time like I'm supposed to and I've missed pills before. Sept 1st-3rd I had a period and on the 4th-6th I had unprotected sex with my boyfriend. I'm on the brown pills now and I'm bleeding but it's not a normal "period". I always have severe cramping but this time in not. I've been waking up dizzy and nauseous the past couple of mornings. And my breasts seem to have gotten bigger. Plus a week before my "period" I noticed that I was spotting. Could I be pregnant or could my body possibly play tricks on me? I've been diagnosed with IBS and overactive bladder so some pregnancy symptoms are similar to my diagnoses.
Thank you so much for your time.