Concerned for my daughter. Ovarian cysts/cancer?

Hello, I’m writing out of concern for my daughter (22yrs). I apologize if this ends up being long.

Mydaughter has always suffered from “difficult” periods. I wouldn’t call them out of the ordinary but she was always dealing with heavier flows and a lot of bad cramps right before starting and during the first couple days. About a year and half ago she was at work and experienced sudden sharp pain on one side near her ovary (she has always dealt with ovulation pain with but it was always fairly mild). It was so severe she couldn’t move and was near tears. It was a severe, stabbing pain. My sister had a ovarian cyst at around the same age and I remember the terrible pain she was in and this was identical. Over the next couple days the pain slowly subsided and I got her in for an OB appt a few days later. By this time she was feeling almost completely free of pain. The OB did not perform an US and said based on symptoms it sounded like a cyst and offered to put her on BC to see if symptoms would ease on her next cycle. She said “if you don’t experience pain the next cycle, it’s pretty much a guarantee it was just a cyst. BC will help with that” and it did. For the last year my daughters ovulation pain has been minimal, sometimes nonexistent and period cramps are greatly reduced as is her heavy flow. She was super happy to finally have “easy” periods. However she has had some things that are odd. Her period blood is always very dark brown, sometimes almost black the entire time. It was never this way before BC. Her periods are lighter and shorter on the pill but the color seems unusual to me especially after this many months on the pill. About a month ago she had a terrible attack of abdominal cramping and diarrhea. She said the pain was so awful whenever she tried to push. It took hours until she finally was able to go and then she went a lot of diarrhea and the cramps went away. Since then she has had diarrhea at least once a week this month with mild cramping. She has always suffered from constipation (she had a lot of undiagnosed food allergies growing up) but now it seems to be alternating between diarrhea and constipation. Then 2 weeks ago nausea started. Last week she was nauseas all day every day (no vomiting). This week has been better but she still gets bouts of nausea. She has an appetite and eats but it is much less than normal. She’s been waking up in the middle of the night with the shakes and feeling nauseas. She has no pain, no bloating, no frequent urination and periods are regular. Just the weird cramping diarrhea episodes and now the nausea. I wouldn’t have thought anything about this being connected to her ovaries if it wasn’t for the cyst she had a year ago and the odd blood color she has now. She does suffer from lactose intolerance and has some food allergies but these are all controlled with diet mostly.

Am I being crazy?. She’s getting ready to graduate from college in a few weeks and is so swamped with classes she hasn’t had time to see her OB yet. As soon as she graduates she’s going. Any advice? Tips? Insight? I’ve also considered possible endo. I’m just so worried for her.