As a general rule, if it's cooked fresh it's safe, if it's commercially produced (thus pasteurised) it's safe, fresh out of a sealed package most things are safe. Avoid cut fruit unless it's prepared fresh in hygienic conditions especially in warm climates (whole fruits are fine).
Avoid foods containing liver, cooked foods that you eat cold from the fridge more than a day later (eg ham is ok out of a sealed packet but not 4 days later), uncooked seafood, unpasteurised soft cheese (hard cheese like Parmesan is fine).
But most foods are safe. I would suggest avoiding salad bars, hot buffet restaurants, and be sensible if confronted with a cold buffet (go for cheese & pickle rather than prawn). Even sushi is ok, just avoid raw fish types. If you do reheat food make sure it's piping hot and it's no more than 24 hours old.
Hope this helps. In my life I've only had food poisoning twice, once from an Indian buffet in the USA, once from watermelon on a Greek beach - food standards are good in the U.K.
I'm sure you will have more worries, people can allay your fears, hopefully your midwife can help you relax about things too. My midwife was great, she had practiced in various countries as a volunteer for msf so told me all kinds of hacks that work, all the things that don't matter etc. helped me put things into perspective, she left to work with Bedouin women just a few weeks after my dd was born