boyfriend and best friend. would you be upset?

So recently my best friend has been having trouble with her boyfriend and they broke up. A little before that I guess she started messaging my boyfriend on Facebook all the time. Literally everyday. And my question is why? I am not one to go through my boyfriends phone he asked me to pick it up and open it, he had an unread message so I went up a little bit as far as I could go and tried to read it and she was talking about how she broke up with her boyfriend and if I told him about it yet, I personally don't see any signs of flirting from what I saw. But then we announced we were pregnant on Facebook and since I picked her to be the godmother she tagged us in a post saying it wasn't just us it was my boyfriend, me, the baby, and HER in capital letters. I don't know why I'm being paranoid or if I'm just pregnant and over thinking things cause I've been depressed lately...