thanks for the query,
Folliculometry is a series of Ultrasounds done to determine how eggs (follicles) are growing in the ovaries. Folliculometry is normally done with transvaginal ultrasound
. It is started on day 2 or 3 of periods with a baseline ultrasound to see the baseline status of the ovaries prior to starting stimulation of the ovaries .
In your case follicular growth is increasing normally. It is about 2mm/day.
On day 15 R.O-13mm might be subjective error or ovulation has occurred with irregular follicular shape.
Ovulation usually occurs on 14 th day when follicle size is between 18-22mm.
ET(endometrial thickness) of 7.5 is good.
What i recommend you is to continue folliculometry till your follicle size is between 18-22mm followed by hcg
Chances of conception per cycle after ovulation is 18-22%.