You married Megatron and became pregnant by him. Knockout was the first happy one, because he was your best friend and he was a doctor: so he would take care of you during the pregnancy

Then you had a miscarriage, but he himself didn't know why, plus he couldn't find out because of his lord's cries

And that's when he knew why: It was your first pregnancy and since you were carrying a Cybertronian baby your body was like...'rejecting'. In basic you were too weak to wear sparkling for a premiere

You were lying on the bed when he arrived

''How are you doing? I knew the reason: you are too weak to carry Megatron's baby from the first pregnancy'' Knockout lowered his voice