Pregnancy scare 😱

My period was supposed to start today and it hasn’t. I’m ALWAYS punctual with my period. Me and my boyfriend have sex regularly usually with a condom but have used the pulled out method a couple times. He also wears a condom just at the end when he knows he’s about to ejaculate (any pre-cum not caught by condom). Usually I feel my period coming on but my symptoms aren’t all there. I’m having cramps but they feel milder and my back is just really hurting. I’ve been nauseous and lightheaded too. Should I be worried?