Confused

Natalie • TTC 3.5 years ❤️ 1st round of IVF 3 eggs did not make it past day 1 Second round 5 eggs 2 fertilised and did not grow 💉

I am currently doing ovulation induction and my doctor has prescribed ovidril as my trigger shot and then 5 days later I need to have pregnyl arnt they the same thing ?

So confused as to why I need to trigger 5 days later after my ovidrill?

Any help please!