Ovarian cysts are small fluid-filled sacs that develop in a woman's ovaries. Most cysts are harmless, but some may cause problems such as rupturing, bleeding, or pain; and surgery may be required to remove the cyst(s).
51mmx44mm is 5.1cmx4.4cm in size. The recommendation for surgery usually begins at 5 cm. This sounds like a fluid cyst, so it has the potential to get even larger. The bigger the cyst gets, the bigger the surgery to remove it. Some fluid cysts can resolve on their own, but at 5 cm, it can be unpleasantly painful if ruptures. Since you already mentioned pain, I wonder if the cyst is leaking/breaking down or if it is pressure pains you feel from its size. If the cyst is reducing your quality of life, surgery makes sense, but not if it can resolve without surgery. What does your doctor think?
Blood in the urine sounds more like a bladder, kidney or urinary tract infection than a cyst.
My right Ovary became 9cm in size, located after continious lower right quadrant pain, irregular periods. The Doctors were unable to definitively tell me that it was 'not' cancer, without operating. I had an Oopherectomy done a month later, and found the Tumor to be benign fluid filled: no cancer.
You will instinctively know what you are dealing with, but if you are not comfortable with the information your Doctors have told you now.....get a second opinion.
Basically you need to get advice from a doctor, he or she will advise you whether you need surgery or treatment of some type.
Ovarian cysts in people of your age are very rarely cancerous, but as you are experiencing symptoms such as pain and you may need some treatment to relieve the pain and get your periods back to normal.
There is a lot of information available on the net, if you enter adnexal ovarian cyst in the search bar you will be able to get lots of information and this will explain what these cysts are, the symptoms and the kinds of treatments available.