We conceived both times on holiday and I did many things that I probably shouldn't have - both times! However none of these seem to have had any impact. Both times I was drinking prior to the BFP (as I was sure I couldn't possibly be pregnant!).

I rode bikes on cobblestoned streets, went white water kayaking, rode elephants, went surfing, went skinny dipping in near freezing water I wouldn't wrap yourself up in cotton wool just in case. Do what you want, have fun and relax.