Buying a house with poor credit, but 20% down and 3 years + work history?

It's going to come down to how recent was your poor credit. If you still have past due bills on your record, you need to bring them up to date and then make payments on time to rebuild a positive history. If the bad credit was 1 or 2 years in the past and you have been rebuilding your credit by paying things on time, you may have a decent chance, given the down payment and recent positive history. If Kroger offers membership in a credit union to its employees, that may be the place to start.