Follistim.... HELP!

So this is my first round after ttc naturally for almost 2 years. Im on cd 5 I went in for my US today after 3 days of 75 units. My dr is very blunt and to the point and just said everything looks good and kept me on 75 for three more days so I’ll go back cd 8 for my next US. Can those that have used follistim or like meds tell me how many cycles it took as well as if only needed 75 units rn a good thing? I’ve read on some that they were on higher doses so I’m hoping this is a good sign. Also about how many days in the cycle did you have to do follistim before your trigger shot like 10-12? And help and information would be amazing!!