Pregnant??

I have a question. I had sex for the first time in months this past Sunday. It was unprotected. My period was supposed to start 2 days after. But now it's 4 days late. Could I be pregnant?? My period is never late. And it always starts 1 to 2 days before the actual date that eve says it'll start. The only time my period was late, 8 days, was when I did ab workouts & squats for 4 days. I stopped because my period began. That was a very long time ago tho. I haven't changed any routine or anything. I'm the same. Life's the same. So am I pregnant?? I need some advice before I discuss it with my boyfriend.