I get same pain just under my ribs then it goes round my lower back, gets worse with periods, over the counter pain killers won't work been to doctor twice, one said heartburn and gave me ibbrophen which did not work, the other doctors checked my abdomen ask if I feel pain and said it's stress, but it feels like cancer, had test and it's not.
You know your worrying could be making it worse, I find it gets worse when I'm very anxious and coming on period. I was silly and I took a load of paracetamol once which did nothing, went to a&e and they sent me home, the pain started after that. it's been with me for seven years.
Write a letter to your parents only one of them, put it in a brown envelope with a stamp and post it to your own address, do not put mum or dad put their real name and surename, it's coming from you, your not pretending to be some one else. Write it as your writing it. Why can you not go to you teachers. Try not to worry, i think it just unforunate that stress affects us in this way, some people get headaches don't they. Write that letter, Gp will ask where the pain is then check your tummy and ask you if you feel pain. Try not to understand estimate doctors, they know if your healthy as soon as you work through the door. Do not be afraid, mix a spoon of baking powder with water and drink it when the pain starts or you can mix it with milk or drink the milk on its own.
Hope you can identify and I hope this help even if it was only a fraction. I am sorry to hear you are experiencing real pain. Stay strong and, you will see a doctor eventually.
Try to talk seriously about this issue with a parent again. Otherwise, ask if you could get a general checkup with a family doctor, and then you can mention this pain at that visit. However, if your parents do not help you, try to talk to some other adult that you trust, whether another relative, a counselor or teacher at school, a religious leader, for examples.