Colorectal referral after high FIT test

I had some rectal bleeding without pain and with some clots a couple of weeks back, and abdominal pain...  so I went to the GP and they gave me a FIT test to do. When she examined my bottom she could feel no haemmorhoids or fissures. No visible blood when I did the test but it came back at 183, so they've done an urgent referral.

I had the letter from colorectal today for a phone appointment next Tuesday. Is this usual? I'm worried they will fob me off saying I don't need further tests.  

I'm trying to remain positive but am struggling a bit. I know there's so many other things it could be but your mind always goes to the worst doesn't it!