Good to see you again Your Strawberriness.
I think its very normal for a regular checkup to test for iron levels. So I would recommend that you call your doctor and find out how your iron levels were at the last checkup.
They actually have home kits for iron levels. I've seen them in the pharmacy for under $25. Amazon has them for under $15. They require just one drop of blood. A pinprick in the finger does it.
Another option is to go to the blood bank. You only have to be 17. Sixteen with parental permission. It's a good thing to do anyway. and you get your iron levels read to you on the spot. Plus there is the cookie and the juice. If your mom takes you, you might even get out of first period. Many schools have annual blood drives, too.
Anyway, there are lots of more common reasons for being tired than anemia. Most of the teenagers I know don't get enough sleep. They don't go to sleep early enough and the stupid school system has the first period start way too early. Oh, you just started back to school, too. That has to be exhausting. No wonder you are tired.
However, anemia among vegans is a concern. Especially young women. There is a pretty easy solution though. Vegans need a source of B12, and most multivitamins contain B12. And many multis also contain iron. So you can take a multi and solve both issues easily. Multis aren't a bad idea even if you are not a vegan.
For vegans, an iron supplement is not a bad idea. the iron found in plants is less absorbable than the iron found in animal products. Also, some of our favorite foods inhibit the absorption of iron.
I've done a little research on vegan multis and I take the DEVA Tiny Tablets (with iron). They are a minimalistic approach to vitamins. They really are tiny. They are also very inexpensive. Six dollars for a three month supply. That is like 6¢ a day.
DEVAs contain 100% of the RDA of B12 and 50% of the RDA of iron. And normally you don't want to take too much iron in a supplement - too much can cause constipation.
Vegans favorite foods have iron in them anyway. tofu, soymilk, lentils, beans, peas, seeds, nuts, leafy greens, etc.
Cooking in cast iron is also a good solution.
I recently have been using Cronometer every day. It's a way for you to easily analyze your diet. You can check it out. it's free. and once you have it done you can either show your mom how good your proposed vegan diet is or you can make the necessary corrections.
I just recently posted my results here.
https://veganforum.org/threads/cronometer.3009/