Its probably bloating hun. We retrain a lot of water in the first trimester and it does cause us to have what seems to be a baby bump. For example, I got my BFP on xmas eve. Just a week later I was already looking like I was 4-5 months gone haha.
My hubby couldn't believe it either.
It will go down, just give it time but its nothing to worry about and is completely normal. Take care and hang in there!
