How to know if I have Cancer or not.

I have abnormal menstrual bleeding as in I bleed every day for about 4 year's now. at first when I tried to consult a Dr. I was told that it might be because of hormonal imbalance so they recommend me medicine for 3 months I've tried that already but it doesn't seems to work. With this bleeding for year now I also have abdominal pain in morning on my left side on regular basis, sometimes it hurts whole day. But sometimes while it pain it also felt like I'm having cramps in my left side of abdominal. While reading few articles online I read that my health problem is be indicating that I might have Cancer. I'm not SD sure whether I should believe it or not. I'm confused. They also said if you cancer few moles might started growing on your body frequently as wel. Which is kinda creepy to me since it is happenings to me. I just want to know is it true? Does my health problem has anything to to do with Cancer or were articles I read before were scams. Please reply asap. Thank you.