Flixbus/ Greyhound from Chicago to Indianapolis review?

Hi, I am a solo female traveller from outside of the US and I will be going to Chicago, then Indianapolis this October.

Due to scheduling reasons, I have no other choice but to either fly or take the bus from Chicago to Indianapolis. I am trying to stretch my budget by taking the bus but I have heard some horror stories from both companies.

Do you have any tips for travelling by either Flixbus or Greyhound? What was your experience like? I am greatly concerned about delays and safety issues. I would love to take the Amtrak train but unfortunately I have to leave Chicago on a day that the train doesn’t run.

Thanks in advance! Having your advice means a lot to me.