My boyfriend (and now fiance) and I went on a two week break the summer before our junior year of college, after being together since second semester our freshman year of college. We were only were broken up for two weeks and in that time both of us slept with just one other people. We took the break since we had gotten together so young, got very serious very fast and wanted to make sure this was it. The break was really succesful, it was basically all we needed to remind each other we were in love and the two week time was a lot shorter than we had both expected. We didn't really talk about what happened during the break for a long time even though we were both honest about sleeping with someone else. A couple months after being back together we vacationed just the two of us and had a huge heart to heart about it, both of us coming to terms with everything.
Now, the summer between our junior and senior years of college, we are recently engaged and are set to get married next summer, before he joins that army rangers and I go to medical school. I just got back from a vacation in Paris with some of my sorority sisters, coming home early because my fiance said he had some huge news for me. When I got home he informed me when we were on our break the girl he slept with got pregnant and had a baby. He had no idea until the girl got in touch with him while I was abroad. I 100 % believe him, him and I are close enough that we know when the other is lying. The only reason she didn't contact him until now is because she needs money and knows his family is wealthy.
I don't know whether or not to be upset or how to feel at all. I want so much to be supportive, because in all honesty it could have happened to either of us during the break. I don't want to tell any of my friends or family yet until my fiance and his "baby mama" sort things out and I figure out where I stand. The only thing I am certain about is that I love him irrevocably and I don't think this will change the course of our relationship. But how involved should I try to be? I am not angry, but I feel like I should be. Is it ok not to be?