I ended my period on the 12th of November and had unprotected sex on the 14th but he never came inside me. Today is the 25th which 2 weeks after my period and intercourse and my breasts and nipples are extremely sore! I am 23 years old and this has never happened before ever! Could I be pregnant?

You had unprotected sex so of course you could be pregnant. Are you pregnant? Sore boobs are not a pregnancy indicator. At this point the only indicator is a missed period which you should be or not be getting in a week or two. If your late by about two weeks then take a home pregnancy test with your first morning (post sleep) urine.

At this point I would give you about even odds because semen can stick around for a day or two and ovulation can occur at any point throughout your cycle.