Ovarian pain, no period, but cramping?

Hello I stopped my birth control on Feb 20th and had my period on Feb 28th. I was taking Seasonal for 8 months before I had decided to come off of it. My period on Feb 28th was about 5 days long and ended on March 4th. After that my next period came on the 25th of April and stopped on April 28th. In May it was on the 20th and ended on the 25th. The flows were heavier but the latest two were noticably heavier. I had to change my tampon every hour to two hours. Since my period in May stopped I have been having pain on both ovaries, more so on my left side. Sometimes it is dull and sometimes it really hurts. I went to the doctor and she said I didn't have cysts. So my question is what else can it be? Ocasionally I will have cramping but it my periods have been kind of crazy since coming off the BC but before they were always exact.(Came at the same time every month) The doc said there was nothing wrong but all she did was feel around my ovaries, she did no actual test. Any ideas on what it maybe could be? I know you guys aren't professionals but I am just asking for opinions.