I did experiment on myself. I'll say that I have usually ovulation (if I have it) on 20-24 days. I take temperature of my body each day to understand that, after ovulation its growing next day. Well last month I was drinking mint tea in first phase of the cycle and ovulation came on 16th day, which is good. This cycle I did the same I began to drink up to 3 little cups a day after menstruation and was drinking about a week like that but I felt side effect such as felling sleepy, after that I stopped, and ovulation came on 15-th day. And long time it didn't happen to me that two ovulations come one after one like that, long time even i didn't have it so early. But after ovulation its better to not drink it. Mint increase LH hormone which stimulates ovulation. You can find information on scientist researches in Internet.