If they were taken at least 8 hrs apart there probably won't be any effects or adverse consequences.
But, be listening to your body, aware what is going on - be tuned in, for just in case. Never know how the body will react. Then resume medication at the same time in the morning as usual.
You should be just fine.
Boy I sure can push the wrong buttons, sorry):
I am not sure what will happen but I think since it has a shelf life, I would call my doctor and ask his advice. If I might make a suggestion, try keeping a notebook and writing down the time and day that you take your meds. Keep it with your medication and you will have a record of when you take it. If you don't think you took it then you probably didn't and you will be ok. You also could call ask a nurse or poisen control, they may be able to help or your pharmacist. lol linda