Hmm, from the article...
During her murder trial in November, testimony revealed she had lab work done prior to her cosmetic procedures. Plastic surgeons routine check a patient's general health and whether she is pregnant prior to an elective surgery, like a nose job. In fact, Armstrong's surgery was pushed back by a day, a witness testified, because Armstrong failed to get the labs completed. Her doctor's office told her they were necessary. She had the labs done the next day and was able to go under the knife.
So why didn't the labs show her supposed pregnancy?
And wouldn't she have been tested when she was booked? (Unless she specifically refused to take a test.)