By all means, make plans for having pigs in spring, BUT start making enquiries now. Some people seem to think breeders keep weaners sitting on a shelf, waiting for buyers. In reality, lots of litters are booked way in advance - some even before they are born.
If you have a particular breed in mind, start doing your research and looking for breeders now. Otherwise you may end up buying any old thing at market, just because you want to start keeping pigs in spring - and it may not be a wise move.