Heart murmur that didn't go away after pregnancy.

Did anyone develop a flow murmur while pregnant and was told it would fix itself after pregnancy but never did? I was told that's what mine was but my daughter turned 3 this year and I still have one. I've been reading about them and now I'm freaking out. I wasn't born with one my mom said so it had to develop from that. I will see a cardiologist soon but I want others stories about it to try to ease my mind. I also don't have any symptoms of a dangerous murmur (no chest pain, no shortness of breath, no dizzy spells etc)

EDIT: I've done the halter monitor, had 2 ekgs, and the treadmill test. I went initially for palpitations because they were almost constant and found out my murmur didn't go away like it should have (as told by my doctor when I was pregnant) I'm just scared that it's gonna lead to a valve replacement and I'll die in surgery. And now I'm also scared that getting pregnant again like we've been wanting to will make it worse.