It took me over a year, probably closer to the 2 year mark, because of breastfeeding and weight gain and budget issues as well. Once I stopped breastfeeding and lost some weight I started feeling more like wanting to be sexy and by then I could also stretch the budget to some new lingerie, which was much appreciated by hubby
My advice would be to get measured before buying a new bra, so you get the right size as pregnancy and breastfeeding does weird and wonderful things to our breasts and bodies.