When Thea is at the birthing class, Nick is sitting behind her in the beginning and then the camera switches to the back, and he is not sitting with her. But when it returns to the front, he is there again.
When Thea and Lisa were in the bathroom smoking and talking about their boss, just before their boss throws open the door Lisa is holding the cigarette, when the camera comes back not even a half a second later Thea is holding the cigarette.
When Thea is in the dressing room exchanging her fake belly for a larger one the size of the velcro changes back and forth. When the new belly is pulled from the mannequin it is secured by a thin strip of elastic, however in the dressing room it's a thick piece and the old belly has the thin strip.