Hi, Thanks for the query. I understand that you are taking letoval for conception. As you have PCOS, you must have been investigated for hormonal studies. If any abnormalities have been detected, better take drugs directed towards those defects to help in ovulation. Letoval and any other ovulation inducing drug must be used with caution as repeated use makes it less effective. Also it is difficult to say when ovulation will occur. It usually occurs between day 12 -18 but may be variable or may not occur if the dose is not correct. If you are using it, better do an ovulation study to see if it is actually helping and the dose you are taking is all right. Other signs of ovulation apart from ultrasound are thinning of cervical mucus [it becomes watery] and an increase in basal body temperature [measured early morning before getting up from bed using a BBT thermometer] by 1-1.5 degree. Ovulation predicting kits are also available over the counter. I suggest that you see a gynecologist and then begin these treatments for best results. Hope I was able to help you. Thanks for using Health Care Magic. I would be happy to answer any further queries. Have a nice day. Dr. Madhuri Bagde Consultant Obstetrician and Gynecologist