My GP did nothing other than the referral either. To be honest, the clinics' pathology labs typically give more reliable results than the general pathology labs since they specialise in these tests rather than doing all tests. In particular, I've heard of people getting very different SA results at the different labs. The lab at our clinic was much, much quicker with the results too.
What she said!! A good FS will want all their own tests done! Good luck!!