Am I overreacting?

My boyfriend and I had sex using a condom Friday, December 23rd. He came in the condom while it was inside of me and kept going for a little longer. When he pulled out the condom was about halfway off, but it appeared all his cum was in the tip. My period is in 2 days and I'm experiencing back aches, acne, cravings, and cramps so I'm not late or anything, but I'm still freaking out. Based on my circumstances how likely is it that there's a possibility I'm pregnant? This was my first time so honestly I think I may be overreacting. Do y'all think I'm overthinking?