I know that feeling. Has it turned into something that's circulating in your mind a lot and adding to your stress?

It's highly, highly, highly unlikely you're going to die from periods that are running a little long.

It sounds like you're afraid to talk to her because she will tell you to go to the doctor, and that's what really scares you. As she is not a doctor herself, she can't really help you with medical problems, other than probably to tell you what we've told you here, or tell you to go to the doctor. So yes, that's possible.

Here's an idea: prepare yourself beforehand in case she tells you that. Prepare yourself so that if she tells you to go to the doctor, you are ready to tell her NO. If you need to, just decide you're not going at least for now. Put a trip to the doctor on the back shelf. Say "No, I'm afraid of doctors and I'm not going." Then ask her to just listen to your fears, validate them, encourage you, support you - whatever it is you need emotionally that will help you.

I don't know where your fear of doctors came from, but mine came from being physically restrained, treated roughly, and subjected to painful things when I was very sick as a child, so it's the issue of lack of control that upsets me. So this may not be helpful if your fear is coming from a different place, but this is what's been helpful for me -

Just remember, you don't have to go, and nobody can force you. Push you, encourage you, sure, but not make you. You are a legal adult now. You are in control of your healthcare, including making decisions about when and when not to seek care. It's okay if you don't go. That is your choice. There may be consequences to your health if you do not go, but it is still your choice. You have the power to make that decision. So make that decision to say NO if you need to. Own that power.

The reason I encourage you to do this is because I have found that owning my control and autonomy has helped me get through some things that scared me a lot, including going to the doctor. Learning that it's okay and within my rights to say "no" helped give me greater confidence because I knew then that if I said "yes," I could revoke that "yes" at any time if it became too much. I can walk out the door any time and never go back, and no one can stop me.