I'll be the first to admit I've never bred my balls...but I did purchase a possibly gravid female yesterday, so I'm on the lookout for building behavior. I've done my reading and I've discovered that pre-ovulation sheds can be quite unreliable. Sometimes they can easily be mistaken for normal shed cycles. However, if your girl did just recently shed and is going back into shed, then this upcoming shed could be your pre-ovulation shed.
Also, you can keep pairing until the pair don't show interest in each other or until she ovulates. Good luck!