MY boyfriend has mono...Do I??

My boyfriend was diagnosed with mono the day after we went home from college. We'd done a lot of kissing during what the doctor called the incubation period. What are the chances that I will get it and when would the symptoms present themselves? A few days before we went home his throat had been bothering him and he had a headache and when he got home his throat was so swollen that he couldn't eat. His doctor put him on steroids. Since than I have had a constant headache but thats all. What are my chances of not getting it?