You don't need to soak seeds so long. Soak them overnight only. Seeds are alive and require oxygen to survive. By soaking for a couple of days, you may have drowned the seeds. Some gardeners have better luck by wrapping the seeds in moist paper toweling rather than soaking them in water. Cold soil temperature could also be the culprit. Your garden may be in a microclimate that is not conducive to seed sowing until a bit later in the season. Instead of planting seeds directly in the ground, plant them in seed starting mix in pots. Put the pots on a heat mat to keep the soil and seeds warm until they germinate. Transplant seedlings to the garden later, once they are established. Another option is to sow directly in the garden later in the season, when the soil has warmed sufficiently for rapid germination.