I went back to the hospital on Tuesday to get my port sorted out. Me and mum went up there in the morning as Judith said to come in early, but it took forever as there was so much traffic on the M3.
When we got there Judith got the needle ready and cleaned the port area. She put the needle in and this time it looked like it should do when the port has been accessed. And it flushed all fine without any problems! Looks like the needle just didn't go in correctly last time!