Could be either. I was hospitalized in 2011 after taking a thousand pregnancy tests. Ovarian cysts have almost identical symptoms to an eptopic pregnancy. In less than a month I went from a size 9 to such abdominal swelling it looked like I was due any day and I couldn't button my size 13s! It was the most horrible pain I had been through next to giving birth. Move was a leaking cyst in my right ovary. Either way you should see a doctor. They would want to do a biopsy if it is a cysts to ensure it isn't cancerous. Good luck!
Either thing, probably. Dizziness was my first pregnancy signal, but since most pregnancy signals come from hormones and an ovarian cyst can play heck with your hormones, all you can really say for sure (absent a pregnancy test) is that you are feeling hormonal symptoms.