I was kneed in the nose so tell me why this happened?

basically, i was sitting in a warm room and wasnt cold and then my mate kneed me in the nose accidently (but she is big and butch and im small) i didnt feel that part of my nose for about 10mins and then i felt loads of pain and it felt like a bruise was coming on :/ apparently i was lucky it didnt bleed? was i ? and why couldnt i feel it for 10mins ? thanks youuu xx