Progressive numbers in index and middle fingers 3 months after surgery

I had carpal tunnel release in march on my left hand (mild). My initial symptoms ere night time numbness which settled quickly after a successful operation and healing went well with no problems. I did have a very slight numbness on the inside edge of the tip of my index finger which persisted but it didn't worry me too much. However today the numbness seems to be spreading and I now have altered sensation in the top half of both my index and middle fingers. I have had a Busy weekend but don't feel I particularly overdid it. I know it's only changed today and obviously I'll see how it is in the morning but I must admit I'm quite alarmed that after 3 months why this suddenly came on today? Has anyone experienced anything similar?