Different amount of purchased songs on pc to MBP

Hi, I have itunes match and I think this is a question for this forum. On iTunes on my PC I have 1000 songs in Purchased, 1236 on Apple TV and only 647 on my MacBook Pro. I am sure the MBP had 1000 yesterday. How do I get the MBP to have all purchased material which is what I thought match did. My match subscription is due tomorrow but is automatic renewal, just in case that is relevant.

Regards

Jules