RE update

So I had my u/s today to see if this Viagra cream is working...its not.  At least not as far as he can tell anyway.  I didn't even have a follicle for him to measure.  I told him that sometimes I can O as late as cd23, so he's having me come back next Thursday to make sure I'm not O'ing from a floating ovary and to see if my uterine lining has improved at all.  If it hasn't, then we are talking about trialing a low dose of FSH to see how I respond to it.  He said if money wasn't an option he would want me to go straight to IVF to do a single embryo transfer.  My only question is if my uterine lining is poor, how would IVF help?  Is it the fertility drugs themselves that would help?  Its all so overwhelming.