Shoes

So my LO has been walking since his first birthday. I meant to get him sized for shoes but with everything being closed when he turned one I did my homework and figured he was a 5. Recently I wondered if it was time to size up but consulting my husband he stated 5 was still fine. I decided today to get my son measured and found out his longer foot is 5.5 inches which mean he should be in a 6 now. I feel so horrible that I've been stuffing him in shoes that are too small. Please someone tell me I am not the only one that finds it hard to determine whether the shoes is too small or big 🥴🥴🥴🥴🥴😭😭😭😭