Idk if I’m pregnant 🤰🏽 🥲

It’s been a week or so since I have had my period but my period was short and unusual we had unprotected sex once but he said nothing came out when we did it bc he didn’t finish inside or near my vagina, my period was mostly old dark blood the firt 2 1/2 days then a little more blood like half the pad which is weird bc I usually fill it up. Then the next day or so it was just old blood. Before my period started I kept having headaches, nausea and my nipples were super sensitive and sore which was weird but now it’s gone after my period but my lower abdomen is cramping a little and is sensitive and I still get nauseated sometimes tooo plz I need help to determine if I’m pregnant or not 🥲