SO got another girl flowers

Would you be mad if your SO got another girl flowers? My Boyfriend got his friend flowers and a card cuz she had an interview she was nervous about an left them on her car so when she came out from it she would find them. She made a huge deal about how great of a guy he is on FB. I've told him that I don't believe he's never slept with her previous to our relationship. This girl has also invited him up north with her and 2 other girls. Didnt invite me just him. It's just weird to me. The only time he gets me flowers is when he pisses me off and he's apologizing. I'm also 8mths pregnant. I've just never had a guy that I was with do this so I'm confused as how to feel.