"EPAU visit"

I attended the EPAU for an early pregnancy scan having been bleeding for 5 days. The scan showed an embryo and heartbeat. However, 2 days after the scan I started spotting again. I left it a few days to see if it cleared up. It didn't. So on the 5th day I rang EPAU to see if I could get another scan for reassurance and to find the bleed. The Sister said because after the scan last week I had been discharged by them I need another GP referral. There are no GP appointments today. I know of other trusts who have a self referral system. It's the same pregnancy so why can't I be seen again without another referral?