Hello and welcome to HCM.
Thank you for your query.
The description of pain and all the other symptoms match that of
endometriosis. Although you have not mentioned the location of the cyst, I am assuming this is a
chocolate cyst present in the ovary, which can cause exactly the same presentation you are experiencing.
Although the presence of pain behind the navel could also be a sign of other complications, like adhesion's, caused due to the same condition, I am sure these can be diagnosed during the laparoscopic intervention that will most probably be selected as the surgery of choice. Do not worry, surgery will surely help relieve your symptoms. In the meantime, you could request for pain management medication in the form of NSAIDs or
hormonal supplements.
This is purely due to the endometriosis. Do not worry, all should get better after surgery. I wish you lots of luck and a symptom-free life hereafter.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications at: http://doctor.healthcaremagic.com/doctors/dr-shoaib-khan/64581 . I would gladly help you.
Best wishes.