Am I being unreasonable/immature? *updated*

My husband and I married spring of this year (2019). We have only been living together since fall 2018, but we felt ready and even now, we are happy together. He’s a wonderful, responsible, loving stepfather to my child. We have furniture from his old place because furniture is expensive and we are not in a financial situation to replace everything. I am very particular about interior design and have been changing the appearance of our home with him to suit our style over time. Previous art and furniture are from his past relationship — furniture they picked out and purchased together. I don’t mind keeping the couch or dining table, because they are still good and there is no need to invest hundreds of dollars to replace them. However, I have disliked our living room rug for as long as we have moved in together. I just have been unable to find one I love enough to spend money and replace it with. Just found out today that his ex picked it out and I felt a little annoyed. It feels a little bad to have our own home with stuff she picked out for theirs... am I being immature/unreasonable? He doesn’t mind if we go shopping for a different rug, he just doesn’t have a strong preference on the rug and seemed uninterested in replacing it until I expressed how I never liked it this entire time. He thought that was sad and suggested we shop for a rug together. I still feel annoyed that we just had this ugly rug she picked out this whole time.

*update: thank you ladies for your input. I’m over it now because I do realize it doesn’t mean anything in particular to him, he’s just indifferent about it and yes, I could’ve changed it. He even suggested we shop for a new one together since I dislike it so much. I’m grateful to have a loving partner and will try to be less petty. I’m just emotional and easily jealous 😅