Nether Portal not working and taking items

When I enters a nether portal, it showed the beta load screen as normal, but when it finished loading I lost my diamond sword and pickaxe(they were the only things I had on me) and spat me back into the overworld, I never died. The second picture is proof I had diamond equipment because who wouldn't craft diamond equipment ASAP. This was on vanilla Minecraft with no texture or resource packs