It's not uncommon for females to lock up at the very beginning of breeding season and then not do anything for a while ... these locks alone do not usually end up with the female becoming gravid ... In my collection, I usually see a series of locks right when I start pairing in the fall ... the a decline in activity through the next few weeks to a month or so (sometimes longer) ... and then increased copulations in January and February.
If she ovulates, I would definitely warm her up immediately .... but unless I could feel very large follicles (or eggs) I personally would just keep breeding her.
Hope this helps.
-adam