Sex is the last thing on my mind most of the time! I have a midwife friend who really pushes sex to bring on labour. I say go for a good walk, sit squating (not sure if that would help but sounds good lol) and just try to relax till it happens. it will happen when its ready too. I don't think anything will stimulate it before its ready. I think if you are overdue its fine to try & encourage labour but before hand.... just enjoy it best you can till its all over, pg that is.