I think I’m pregnant

So I take birth control, making my “cycle” 28 days long, i recently had surgery and had to take antibiotics for the first week and half of my pill packet. My husband and I spaced and had sex 5 different times about a week into my pill packet, with me taking antibiotics that cancel out birth control. Today is supposed to be my first period day, this morning I woke up and had raw egg like CM with a little bit of blood. the past two weeks I have been dizzy, feeling sick, gotten pounding headaches and weird stomach pains that only go away if I eat every 20 minutes or so. And today not taking the hormones pills I have had no dizziness, sickness or stomach problems. Am I pregnant and my body was just overwhelmed with hormones in my body and the pills or I’m I just having a really bad side effects to my birth control?