The phase of menstrual cycle in humans that last for 7-8 days, is:

The phase of menstrual cycle in humans that last for $7-8$ days is ovulatory phase. During this phase production of FSH decreases while that of LH increases which leads to ovulation on about the $14^{\text{th }}$ day. But it may range from $9^{\text{th }}$ to $16^{\text{th }}$ day (approximately).