Bidding on a house

So me and my husband is bidding on a house that would be absolutely perfect for our family. Anyways, I’m trying not to worry about it until the last minute. We still have like 21 days until the bidding is up. But I went to bid and it keeps saying I’m outbidded? Why is it saying that when I bid more? There’s only a 250 inclement.... or can I higher it somehow?