So 2 weeks ago on Wednesday (yesterday) was 24 Jan. If her period really is due today, then 24 Jan would likely have been a fertile day. However, if this cycle were 37-40 days long, then 24 Jan would not likely have been a fertile day. The app works on averages, and so the dates are likely to be in the app somewhere.
It seems unlikely, from the little you have said, and assuming that had been your only sexual encounter, that she is pregnant. Nevertheless, if her period hasn't started by 14 Jan, a test should be reliable.
Presumably, if you were making food, you would have washed your hands. That makes pregnancy even more unlikely.
I had assumed you were with her all night by the way you presented the scenario. The full picture needs to be given to be able to have reliable advice!
One week ago on Wednesday (yesterday) was 31 Jan. If her period really is due today, then 31 Jan would not likely have been a fertile day. However, if this cycle were 38 (or more) days long, then 31 Jan could have been a fertile day.
You need to say exactly what you mean.
If semen is put into a container, it can last a very long time. The vitality of the sperm therein would diminish, however.
If semen enters a woman's vagina, it can last a long time, and the sperm therein can survive up to 6 days.