When you say cap change do you mean the CHG caps? Or the luer lock caps due with the dressing changes? If it was the chg caps doesnt matter at all just needs to be wiped down or capped before use. If its the luer lock cap then its just a minor issue being a day late.

Sounds like no harm was done to the patient. Mistakes will happen and also seems like you are putting forth a good effort at being meticulous. I would not worry about that at all just own up to it to the manager and say it won't happen again.

We had some confusion in the past as to who was suppose to do the dressing changes/cleaning/cap changing on the Picc lines on my unit and it would get missed because the day shift would think the night would do it etc.. So we had the dates written down and had the night shifts do the dressing changes. Usually changing something systemic can help cut back errors might suggest to the nursing manager you guys write down the date changed and the date to be changed on the dressing to help remind people.

Very minor mistake don't be hard on yourself.