If i miss a pill in my tri-sprintec pack and i have sex with a condom but it rips id it possible that i might be pregangt

Of course. It's possible to get pregnant if you don't miss a pill, or if a condom doesn't rip.
Do you think nature designed the sperm and egg to be wimps?

No I mean I miss it like in my 3rd week

I meant, it's possible to get pregnant if you miss a pill, if you don't miss a pill, if you use pills and condoms together and don't skip any and none break - in other words, it's ALWAYS possible to get pregnant, and quoting probabilities is not going to be meaningful. If you happen to be one of the women who beat the odds, then you are just as pregnant. All you can do is wait, and if your period is late, start doing tests.