My fiance is weird about me drinking.

I just turned 21 two and a half months ago. I obviously got really drunk on my birthday and had a lot of fun. My fiance (girlfriend at the time) was happy that I was having fun. I drank a bit the week following my birthday, then stopped really drinking much at all. For the past two months I’ve had on average maybe one to three drinks a week. Tonight after work, I went to the abc store to get a new bottle. I had a bottle of crown royal that I got two months ago, shortly after my birthday. I just finished it last week so now I got a new one. I was bringing my fiance some food and stopped at the abc store before getting the food. I told her this so she knew why I was taking a while to get to her. Then when I get home after seeing her, we’re texting for a bit and everything is fine. Then she mentions how it just clicked for her that I was making a drink tonight because I also mentioned I was getting lemonade from the gas station on my way home. Then, she started texting kind of weird;like kind of reserved or shut down. I had a strong feeling that she was upset with me, and I’m not sure why. She knows I don’t drink a lot, and when I do I don’t get super drunk. She also knows I’m home for the night and I won’t be driving anywhere. I asked her why she was upset and she just ignored my question, then stopped texting me back. She does that every night (ceasing to text me back I mean) because she just goes to sleep without really saying anything to me, so that’s nothing new. But idk it feels like she was mad at me for having a drink after work. Idk what my point with posting this is, it just kind of stressed me out and wanted to get it off my chest. Thanks for reading