I had this. I was seventeen and in the upper sixth doing my A levels.
I came home from school in severe pain. My mother took me to the A and E department and I was operated on the same night. This was early November and I didn't return to school till the new term in January.
Years ago I had what turned out to be an ovarian cyst which the gynaecologist registrar insisted for months was me being constipated! Only when I underwent what was supposed to be an exploratory did the truth be revealed. I had to have a complete hysterectomy and lost both ovaries too. I was 36 so a very early menopause for me! listen to your bodies girls and always, always insist on a second opinion.
This happened to me many years ago. I had intermittent but worsening pain in my lower left side. My GP referred me to hospital for investigation. The consultant I saw subjected me to a very rough internal and external examination and said I needed a laparoscopic investigation for a suspected ovarian cyst. That night I was in awful pain until I suddenly felt something pop. After that there was no more pain and I cancelled my hospital appointment because I felt it was obvious what had happened. I had no more symptoms. But, I guess I was very lucky there was no bleeding. I hope your daughter recovers quickly.
I had this over 40 years ago so although medical treatment may have changed I'm sure the symptoms are the same. Around teatime I was seized by a sudden and excruciating pain in the right side of my abdomen. When that subsided I was left with intermittent pain. I had no idea what was going on but I had a warm bath before going to bed and having a very disturbed night. The next morning I went to the GP who suspected appendicitis and sent me home with instructions to go to A&E when it got worse. At the hospital they agreed with the GP's diagnosis but when they operated my abdomen was full of blood from a ruptured ovarian cyst. They removed my appendix and the cyst. I had no idea I had a cyst but the pain was acute and recovery was rather slow and uncomfortable. Thank heavens for my Mum who came to look after everyone, including a newborn. I wish you well Sparklefizz