detailed and long, please respond 😊

So on Wednesday of last week I had unprotected sex with my boyfriend. At the time I had 17 days until my next period. I've been on a combination birth control pill for years. I missed one pill Tuesday night and took the pill I missed as soon as I woke up Wednesday morning. Then after the unprotected sex that day, I got back on schedule and took my pill at the correct time. I've been on track ever since. I only missed one combination pill. I have 12 days as of today until I start my period. I have super sore breasts, is this a pregnancy sign or a period sign? I always get sore breasts close to my period. So please comment what you think. Thank you!! Xoxo.