Ovarian cyst - BRCA1 carrier

I am 34 years old and was diagnosed with a 3 cm complex ovarian cyst on my right ovary. I have been told that ultrasound has shown it to have features of a dermoid.
It was diagnosed after I went to hospital with severe abdominal pain. Since the pain my last two periods have been abnormal with days of spotting before and after period.

I am a carrier of the BRCA1 gene. I went to see my gynecologist who told me that a dermoid cyst would not cause abnormal bleeding because they don't let off any hormones. Can anyone shed some light on what might be causing the abnormal bleeding? I find it odd that it started at the same time I was diagnosed with the cyst. Thanks for any help.