Isn't it to soon to get another ultrasound after only 1 month for complex cysts, will anything change? is there any other tests?

Complex cyst: If the cyst is most likely a hemorragic cyst, these are functional cysts that result from an ovarian follicle enlarging and not rupturing to release the egg as it normally would. They typically resolve in a matter of days to weeks so there is a good chance it will be gone in a month. Sometimes the follow up is 6 or 8 weeks, but 4 weeks not unusual.