I agree with anniebrooke. Apps are just calculators of numbers based on what you put in and aren't checking your hormone levels. We can have off cycles and never know when we ovulate out of the blue. But they DO help predict when for sure. We are most likely to get pregnant on days 10 through 20 of our cycle. Anyway, that you also used condoms, that's great. That means the odds are very low that you'd be pregnant. When condoms fail, they mean things like condom breaks which you don't mention. They are quite noticeable when that happens. Things that make us late are stress, illness, changes in routine, weight gain or loss or just a blip in hormones out of nowhere. I would try to relax and see if your period shows up. Has it yet?
It sure doesn't sound like it. Tracking apps aren't 100%, because ovulation can shift and not resemble the ovulation in the prior month as regards to timing. But if you had sex with condoms and he didn't ejaculate inside, and then you had a negative pregnancy test after one would have shown positive (if you were pregnant), nothing here suggests pregnancy. Stress can make a period AWOL, and also, if your monthly timing is changing it could also affect your period. Test again tomorrow or the next day, if your flow is still a no-show. But remember, sometimes a woman can skip a period just because.