My upcoming termination

Today I had a consultation I was expecting to find out I was 7 weeks pregnant maximum but the lady did the scan and told me I am 11w 3d and I saw the little picture. I still want to go through with the abortion but that’s just really been a shock to the system I wasn’t expecting to be so far gone as I was on the combined pill and now am experiencing guilt my termination isnt for another twelve days as it was first available appointment as I have to get surgical but I will be coming on to 13w by then.

How can I shake this feeling ?