Fibroids in pregnancy

So I had my 12 week scan and was told that I have fibroids which I found quite weird as I never had them two weeks ago ( this is my 5th scan). I’m already a high risk pregnancy and can’t deal with much more stress with this pregnancy but want to be informed as much as possible as the most information I have been able to get is on google so would like to hear from anyone who has had these and has it had any effect on ur pregnancy so far I’ve had on and off pain with no reason for it the doctor said sometimes they can cause pain but that was the most information that I’ve been given about it.