Corpus luteum cyst-How serious?

My wife is 3 months pregnant and complaining of sharp sudden pain and some internal bleeding which came out in the form of bloody urine. I had her checked and it was found to be corpus luteum cyst. The doctor says there’s nothing to worry about. Is he right? I want to know how serious is corpus luteum cyst? Can this in anyway lead to a miscarriage or pregnancy complications I want to know? Anybody has similar experience?