Spouses children

My spouse has a child with another woman. She didn’t tell him about her until after a year (2yo now) and she doesn’t want him to really be involved passed seeing posts on fb/occasional messages. Am I a bad person for feeling kinda jealous/ hurt when he talks about her? I can’t have children and have had a few miscarriages so it’s a touchy thing for me and I’ve dated men before with kids it just never went on long enough. I don’t mean to feel this way and I love kids, my heart just aches when he sends me pics and gushes. I love him and love his happiness so I’ve never said anything that’s why I’m making this post.