Had a 16mm follicle when ovidrel was given. Was it given too soon? Will there be a delay in ovulation despite the trigger shot?

Of course. the best person to be answering this question is your treating infertility doctor. Most experts would say that the ideal follicle size associated with maturity of the egg is 18-20 mm or larger. There certainly could have been other additional factors leading your doctor to administer the hCG. My understanding is that once the "trigger" hormones are given, the egg will be released/ovulation occurs.