<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, I m trying to conceive and I have been taking ovulation tests and last week I got a positive smiley face ovulation test, then negative the next day, then positive the day after that, and today 1 week later I got a positive again! what does that mean? why could that be hapenning?  <response>: Hallow Dear, This dilemma seems to be either due to error in the kits or personal error. Delayed positive test could be due to exceptional additional delayed ovulation from the other ovary. In such confusion, I would advise you to take the help of ultrasonography. Ultrasonographic ovulation monitoring has an edge over the kit:1. It gives visual evidence of ovulation.2. It informs us about the size of the follicle when it ruptured to release egg. Follicles between 18 mm to 21 mm size give best results of pregnancy. 3. It informs about the endometrial thickness also. For successful implantation, at least 10 mm thick endometrium is lucrative. I hope this helps you. 