I stuck to the rules I was following. Having said that the 'rules' I was following were from a government health department notice about people at high risk of being affected by listeria (elderly people, pregnant women) so it was factual 'rules' and didn't include some things that I think are a bit of here say and information from the grapevine rather than having much researched basis IYKWIM.
Also, I threw up and had 24/7 nausea all the way through both pregnancies so the mere thought of MOST foods made me want to hurl. So for me it was more of trying to find a small number foods I could stomach rather than ruling out foods. For example no way in the world I could have even looked and cold sliced meats *shivers*.