Another question about Ovidrel trigger shot?

I had an ultrasound today and I have 5 follicles that are maturing. One is measuring 12cm, one is measuring 11.5cm, one is measuring 11cm, and two are measuring 10. I go back in on Wednesday to see if any of them are mature enough to give me the trigger shot. My doctor is concerned that I am producing too many follicles. My question is, if by the time I go back on Wednesday, only 1 or 2 of the follicles are 18cm, and the other 3 are less than that, will I still have too many follicles or do you think they will go ahead and give me the trigger shot? I know this may be a confusing question, but I dont know of a better way to word it. I just cant figure out why he would be concerend about too many follicles, when the 3 small ones shouldnt be matured to 18 cm by Wednesday. thanks for listening, any adivce would be greatly appreciated.