Fourth week of ACTIVE pills, missed pill.

Patient: HiI am on Yasminelle contraceptive pill and have been for 5-6 years.Recently I skipped the 7 day pill free period and started a new strip straight away.So as of right now I am just entering my 5th consecutive week of all active pills without a break. In the fourth week I missed a pill and took it as soon as I realised, which was about 15 hours late. I took all consecutive pills as normal. 3 days after I missed that pill I had unprotected sex. This was 2 nights ago. How likely is pregnancy in this case and what action should I take if any?Many thanks.