No Convictions but criminal charges

Well I guess you can count the traffic convictions but no criminal charges. I am currently serving a Probation before Judgment (PBJ) and it is about to be over in October but in the mean time I am planning of getting this charge expunged. But I guess my question is whether the criminal background check will show this charge or arrest? I technically did the time for a crime that I didn't commit in 2012 while a student at morgan state university. Morgan state university told the police that I called the school and threatened to bomb the school and also harassed an employee of the school when really all I did was have an attitude when I talked over the phone to this person. I felt like they were not helping me or giving me the information I needed so I asked them I guess pretty rudely if I could speak to someone else who could help me. This was the records and registration department. They also expelled me for missing classes and refused to refund me my tuition for the classes I paid for, but that's a tale for another time. Now in the fall of 2014 I will be attending school once again and I will be expunging the charge (PBJ) but I was curious if the school that I will be attending in the fall Criminal Background check would hold this little mishap against me. I would hate to pay for a degree and be denied my nursing license or a seat to take the N-Clex. I tried to contact the Maryland board of nursing but no one answers. What do you all think about this situation?