My Girlfriend And I Had Unprotected Sex Multiple Times And

My girlfriend and I had unprotected sex multiple times and about 5 days later she got what she thought was her period. However, it was over a week and a half early and it only lasted about 3 days when it's usually 5 and was much lighter than normal for her. During this time we had unprotected sex three more times. She never got her period at the normal time she does in the month. Is it possible that she's pregnant? She's my world and I'd be overjoyed if she were, just need a little insight. Thanks in advance!