I struggled with this question - for me buying something was just asking to get my hopes up and leading to disapointment while not buying something was admitting that IVF was never going to work....in the end I did not buy anything until we got our BFP, and even then I waited till after 12 weeks.

I think it comes down to personal choice and doing what ever helps you to get through.

Good luck with your cycle - wishing you a BFP!
FG