Clomid-Follicles-Can someone pls explain?

Kristin • Momma & Wife
Ok long story short...1st round of Clomid 50 mg for late ovulation. Age 24 unexplained infertility. Normal cycles. I'm on CD 20 and had horrible pain in my pelvic area. Went to my dr and he did an ultrasound. I have 3 Mature Follicles that look good, but that could mean multiples if I was to get pregnant. He told me that we don't have to BD anymore this month because everything is already set now we just have to wait and see. I am so confused. I thought the follicles developed before ovulation so wouldn't we still need to BD? Can someone help me? Lol!