ASCUS is an acronym for atypical cells of undetermined significance and indicates mild cellular cervical changes with an unknown cause. They may just repeat the smear in 6-12 mos to check for any changes. I have had this and had moderate dyplasia, which are pre-cancerous cells - No big deal - had cryotherapy, which froze the neck of the cervix - little uncomfortable - but no big deal. Best thing you can do is get retested when your Dr suggests it. That was almost 20yrs ago for me - have been fine ever since :) Dont stress, lots of people get 'abnormal' pap tests and they are very treatable.
I am not sure what ASCUS is, google it. Abnormal pap can mean many things...its a preliminary test not a diagnostic test, so it just shows something amiss could be nothing, HPV is a very common reason for them to be abnormal, its the most common Std in woman. I have a few friends that have had them abnormal and that has been the reason. Its not too serious, I wouldn't worry too much. It could be serious but probably not, just relax until you talk to the doctor.