When to seek fertility help?

Courtney • 👶🏼💙 10/29/16👶🏼💙 6/27/20

My husband and I have an almost 3 year old boy. We conceived him the first month we started trying. Now we have been trying for exactly a year and still nothing! Should I worry just yet or just keep trying? My husband thinks because we have one kid already there can’t be anything wrong, which I don’t agree with. Also in trying to help get pregnant, I have lost 23 pounds since May. Any advice?