Possibilities of pregnancy?

I know that is can happen at anytime, anyplace, with any kind of protection so please spare me that much. I am just looking for some personal experience that may help clear things up before we decide to get another test or head to the doctor. Near the end of last month(January) my fiance said is concerned because her period hasn't come yet. She said she didn't remember when in december her last one occured. She said she noticed a weird discharge, thought she pee'd herself, one day when she used the restroom. She took a test and came back negative. We waited some more and took another test that came back negative. She eventually got her period Feb 7 and lasted till the 10th. It was heavy the first day and very light the rest. Before her period we had no unprotected , but the day she stopped and 2 days after we did. Yesterday, Feb 14, she started complaining of really bad stomach cramps and a lot of pain on and around the sided of her pelvic region. Any idea on what thismightbe?Thanks