What factors make you a high risk pregnancy ?

I’m 10 weeks pregnant and told my friend I’m always so worried to lose this baby because I had a miscarriage in October. She’s always saying yeah I get it because you’re very high risk. I’ve been paranoid about everything even having sex so I haven’t done that even though my doctor hasn’t said anything about me being high risk. I’m just wondering who would be considered high risk? I do also have pcos and hypothyroidism. My OB is treating this like a normal pregnancy though