A miscarriage means something went wrong with Mandy's pregnancy and she lost the baby. Selena had officially announced she was going to be a big sister just three weeks earlier.
Sel found out the awful news while she attending a concert in L.A., and immediately left to go home. She canceled some of her upcoming concerts too.
Demi immediately sent a tweet to Selena saying "I love you." Selena's going to need vrienden like Demi to get her through this tough time.
Let's hope Selena and her family make it through this difficult time.