if your having sex and your partner presses hard enough on your ribs can you have rib pain for days?

Regardless of whether you're having sex or not at the time, yes, you can have rib pain for several days if someone presses hard enough to cause a bruise or perhaps break a bone.  I'm sure you're thinking that, gee, wouldn't I know if I broke a bone?  It turns out that we can ignore an impressive amount of pain depending upon the situation.  In other words, you'd have to be quite distracted, say running away from an assailant or trying to rescue a friend from a fire, or perhaps having great sex.  

Of course, this rib pain could also be coincidental to having sex, and could be due to something else.  Best to check in w/your family physician if this rib pain continues or gets worse, especially with shortness of breath or fevers/sweats/chills.  Good luck!