For each of my collections I had a blood test about a week after starting injections, then an ultrasound a couple of days later. That was it.

I think the synarel means that your cycle is controlled so it takes out the guesswork of when you'll be ready. The blood tests and u/s is like a final check that everything is ok. If the blood tests show you've responded too well (lots of follicles) then they may cut back your dose or cancel the cycle. Likewise if your ultrasound shows not enough follicles.

Like butterfly and lily dust have said, different clinics may do things different ways, but they do them a lot so trust that it will be ok.