My fiancé (29f) is upset at me (29m) for what I see as being a petty reason. How should I got about this?

I just posted this on another subreddit but I’m going into a bit more depth here. So, my fiancé and I have been together for over 11 years. I feel like she’s always getting on me for small stuff, at least I see it as being small. I’ll admit, I’m not a great communicator but I do communicate to the best of my ability. Of course I can get better, but I don’t think it’s something that I can change over night. Anyways, I recently took a trip to help her move back home; she was contracted out to another state for work. The night I flew in she had to work, so her brother who was also working with her picked me up. Her and I had been texting during and after my flight but she got upset that I didn’t tell her my plane had landed. Last week I flew out for my brothers graduation. She asked me to message her when my plane landed, I gave her my word that I would. So the plane lands, I’m talking to my grandmother who was flying with me, and messaged my fiancé after I got off the plane. I guess she went on-line to see when my flight landed and saw that it had landed about 10-15 minutes before I texted her. According to her, I didn’t keep my word. It’s been 6 days now and she will barely talk to me, won’t even say “I love you” before going to bed which we’ve done for years. She now wants to have a “talk” when I get home. How do I go about this? Did I actually screw up? Is she or I overreacting? We’re getting married in 3 months and this is what she’s currently upset about. I’ve never been married before, but I would imagine marriage has larger problems.