Today i feel sick, so cant go to school....should I tell my EX-girlfriend? that i cant go to school tomorrow?

I really want her to be my girlfriend again...we been separate four month...I always try to win her back...but always failed...at school, if I saw her...she only give me a smile...but didnt talk to me...but sometime got...plz tell me...What should I do? Should I tell her friend that i didnt go to school tomorrow? to make her jelous? or juz tell my ex that i cant come to school? Actually I dont know whether she still love me or not...Give me answer today...Thank You...