Tingling Sensation Like In My Heart?

When i think or read something about betrayal..(usually it includes love or something like that -_-' ) or when it's about something sad...which usally i end up crying (yes i sound pathetic,but i can't help it!) i get this tingling sensation in my heart for like 2 secs.It hurts sort of..dont know if you can understand me =( Anyway...anyone can explain why it happens? pwis => ? Thanks