I'd be ringing the department directly to check at least that they'd received the referral. We've experienced far too many times where the GP surgery "forgot" to make the referral.
My son had a lump in his neck and was referred for a scan. He waited and waited. The GP said it could be "a few weeks" so he wasn't particularly worried when he heard nothing. After 3 months he phoned the radiology dept only to be told they'd no record of him! Phoned back the GP surgery and it was all "looks like we didn't send it".
Same happened with me for an MRI scan from the GP to explore my middle aged hearing loss. GP said as it wasn't urgent it could be six months. So I waited and waited, and after 4/5 months I chased the radiology dept to be told the same, they'd had no referral. Back to GP, (different practice) and they said the same, just glibly saying it hadn't been done and they'd do it.
When my young son had an ingrown toe nail and needed part of it removed, same happened, after months of the GP surgery faffing around with it, they finally admitted it needed partly removing and said they'd do a podiatry referral, but again, said it could be months! There's a trend here! We didn't trust them so I phoned up podiatry the week after - what a surprise, they'd had no referral. What was worse was that they said they didn't actually have a waiting list and appointments were being made for the following week for new referrals.
The NHS (and particularly GPs) is hopeless. And no, none of this was recent, we're going back 10-20 years!