I am 12 weeks pregnant. The last two days I have noticed random sharp twinges that last only seconds in different areas around my breast and chest. They seem like they are happening from behind the breast and of course make me worried about heart problems. Right now they are happening on the left side. They feel like someone stabbed me with a knife, but only last a second and then gone. I dont believe it is heartburn because I hear heartburn mainly happens in the middle and goes up the throat and I am not experiencing anything like this at all. Last night I was so freaked out by it that my husband brought me to the ER where they did an EKG and bloodwork and everything showed up normal. They didnt really have an answer for why I felt this but I kind of shrugged it off as maybe hormones or growing breasts? But would I feel this so deep to my chest if it were my breasts growing? It feels like it is my heart/chest more so then breasts. I dont have any shortness of breath, it does catch me by surprise when it happens but I have no problem breathing. Could I have pulled a muscle in my sleep and not realized it?