help!! I'm so scared

so I was previously taking birth control for almost a year, they prescribed me to another pill that within the first three days gave me difficulty, so I stopped taking the pill three days into the pack, I have a steady partner and have a active sex life and we've been using condoms ever since I got off the pill but my period is three days late! but when I got off the pill a couple days after I bled heavily for three days, I'm not sure if that was just another "surprise period" a week after my actually cycle, but I am so scared, I can't remember if my boyfriend and I had sex when I was taking the new pill, but he always pulls out, and we've been using condoms ever since, am I late cause I stopped mid pack?? am I late cause I'm so stressed out?? am I late cause I'm pregnant? I hope not I'm so scared HELP