Hi, I would say that smears are not very often abnormal, but it is not necessarily a cause for concern if it is.
When I was about 30 years old, it took 7 attempts to get a smear from me, because they were constantly returned as inadequate sample. It turned out I had a cervical erosion which was bleeding every time my cervix was touched. After a colposcopy and laser treatment it was all sorted out, and my smears have all been fine since.
But it was a bit of a stressful six months, waiting for the results every time, knowing that I was probably going to have to go back again and again.