What Causes Twinge Feeling While Having Uterine Fibroid?

Hello, my name is Crystal and I am 28 years old. I have been off of birth control for over three years and my husband and I are not using protection. I normally feel the ovulation "twinge" around two weeks after my period starts. My last cycle started 12/23 and the best I can tell I ovulated the week of 1/3. My concern is that I have been feeling the "twinge" for the past two weeks. At first I thought I might have overdone it at the gym but it is such an odd feeling and it is only on my left side and feels just like my ovulation "twinge". I know for a fact that I do not have an ovarian cyst because I just had a sonogram last month due to a uterine fibroid and they checked my ovaries. I have also had a very thin almost clear discharge for the past week or so as well. Can you think of what this could be? I am supposed to start my next cycle between the 20th and the 23rd. I have never felt this before and I don't want to jump to any conclusions.