My daughter has been sleeping on her own since she was 2 months old. We have a routine. However, she…

My daughter has been sleeping on her own since she was 2 months old. We have a routine. However, she has been waking up a couple hours after putting her in her crib and refuses to go back to sleep unless she's in my BED. My hubby & I both work so I usually just bring her to bed with me and she'll sleep til 8am. Is she possibly going through a stage or leap ? She hasn't been like this before....I enjoy the cuddles but I don't want her to learn that she can sleep in my bed. We've done an excellent job with sleep training & stuff...but why now?!?