19 days late period

I’ve had my period for almost 6 years now, since I got this app like 7 months ago my period has come between 30-45 days and never has been this late before. I’m a virgin but I took two pregnancy tests anyway, the outcome on both was not pregnant. I told my mom and she’s making a doctors appointment. I’m not educated well on irregular periods. Does this mean when I get my period it might be very heavy and last for weeks? Or just be spotting? Will my period take a long time to become regular again? Do you still experience the same PMS symptoms or should I always be wearing a pad/tampon Incase? Lmao help.