Hi,
Our maiden bitch (three in October) was mated at the beginning of April which resulted in a phantom pregnancy.
Her seasons are usually 6 months apart but she has just come into season again!
Has anyone else experienced this? Can she be mated again at this point or do I need to wait until her next season?

Less than 4 months between seasons often means that they haven't ovulated (could be reason fro her not conceiving last time). 

Could be the last season was an infertile one with insufficient hormone levels and this time she'd take, could be a split season.

If you have to travel far and pay a stud fee regardless of outcome then I'd do premate testing until the levels show she ahs actually ovulated.

Many thanks for your advice.