Unpredictable periods

[Jenny1]

Hi,
I'm 37 and my periods have been a bit unpredictable over the last few years. They were became very heavy with three very heavy days and two heavy days. I was then found to be hypothyroid and put on eltroxin. My periods got lighter with two days heavy bleeding and one light.
They used to occur every four weeks. Now I have a period every three weeks with 1-2 heavy days then
next to nothing.
Some months I have virtually no pain then others I am bent over with pain.
This month was very bad with a feeling of a cyst on my right side with nausea a week before my period.I then have one day where I feel really good,I have arthritis and that feels better then it goes back to the usual.
I had to pee a lot and my GP took a urine sample and there was blood, protein and ketones in it.
I was put on an antibiotics.I still had that feeling of a cyst that needs to burst. I get this on and off and once it feels like it bursts I feel irritation but then the pain improves.It takes days for my period to start with light spotting before it kicks in.
I have had several ultrasounds but they come back normal so my GP says they can do nothing.
What is going on?

[Mr. Hugh Byrne, MRCOG]

Often your cycle changes as you get older. As long as there is no bleeding between perioda or after intercourse I wouldn't worry. The pain may be due to ovulation and the way to deal with that is to suppress it hormonally i.e. the pill. The urine issue is unrelated.