Sternum pain?

So today I just started having this burning sternum pain. I am worried it’s preeclampsia but I literally just had an appointment on Monday and everything looked good. No protein in my urine, no high blood pressure, and no swelling. Im wondering if it’s just bad heartburn possibly? Or a growing uterus? Idk does anybody have any input? I’ll probably give it another day and if it doesn’t go away I might call my doctor or go in. I just don’t wanna be dramatic if I don’t have to.